Showing papers in "Journal of Andrology in 2008"
TL;DR: Testicular oxidative stress appears to be a common feature in much of what underlies male infertility, which suggests that there may be benefits to developing better antioxidant therapies for relevant cases of hypospermatogenesis.
Abstract: Oxidative stress results from the production of oxygen radicals in excess of the antioxidant capacity of the stressed tissue. Many conditions or events associated with male infertility are inducers of oxidative stress. X-irradiation, for example, or exposure to environmental toxicants and the physical conditions of varicocele and cryptorchidism have been demonstrated to increase testicular oxidative stress, which leads to an increase in germ cell apoptosis and subsequent hypospermatogenesis. Such stress conditions can cause changes in the dynamics of testicular microvascular blood flow, endocrine signaling, and germ cell apoptosis. Testicular oxidative stress appears to be a common feature in much of what underlies male infertility, which suggests that there may be benefits to developing better antioxidant therapies for relevant cases of hypospermatogenesis.
476 citations
TL;DR: It is concluded that the microsurgical varicocelectomy technique has higher spontaneous pregnancy rates and lower postoperative recurrence and hydrocele formation than conventional varicocele techniques in infertile men.
Abstract: To date, there have been no randomized, controlled, prospective clinical studies that compare various techniques to describe the best method for the treatment of varicocele in infertile men. This meta-analysis aims to address the best treatment modality for palpable varicocele in infertile men. A MEDLINE search was performed for articles published between January 1980 and April 2008, and we analyzed 36 studies reporting postoperative spontaneous pregnancy rates and/or complication rates after varicocele repair using various techniques in infertile men with palpable unilateral or bilateral varicocele. Spontaneous pregnancy rates and postoperative complications such as hydrocele formation, recurrence, or persistence were compared among the techniques. In addition, interventional failure with radiologic embolization and reported complications with the laparoscopic approach were reviewed. Overall spontaneous pregnancy rates were 37.69% in the Palomo technique series, 41.97% in the microsurgical varicocelectomy techniques, 30.07% in the laparoscopic varicocelectomy techniques, 33.2% in the radiologic embolization, and 36% in the macroscopic inguinal (Ivanissevich) varicocelectomy series, revealing significant differences among the techniques (P = .001). Overall recurrence rates were 14.97% in the Palomo technique series, 1.05% in the microsurgical varicocelectomy techniques, 4.3% in the laparoscopic varicocelectomy techniques, 12.7% in the radiologic embolization, and 2.63% in the macroscopic inguinal (Ivanissevich) or subinguinal varicocelectomy series, revealing significant difference among the techniques (P = .001). Overall hydrocele formation rates were 8.24% in the Palomo technique series, 0.44% in the microsurgical varicocelectomy techniques, 2.84% in the laparoscopic varicocelectomy, and 7.3% in the macroscopic inguinal (Ivanissevich) or subinguinal varicocelectomy series, revealing significant difference among the techniques (P = .001). We conclude that the microsurgical varicocelectomy technique has higher spontaneous pregnancy rates and lower postoperative recurrence and hydrocele formation than conventional varicocelectomy techniques in infertile men. However, prospective, randomized, and comparative studies with large number of patients are needed to compare the efficacy of microsurgical varicocelectomy with that of other treatment modalities in infertile men with varicocele.
330 citations
TL;DR: The current literature pertaining to androgen deficiency, MetS, and ED is discussed, because the relationship of these factors is of scientific and clinical importance and a better understanding is needed of how obesity, diabetes and hypogonadism contribute to androgens deficiency and the various pathophysiologic states of vascular disease.
Abstract: The metabolic syndrome (MetS) is considered the most important public health threat of the 21st century. This syndrome is characterized by a cluster of cardiovascular risk factors including increased central abdominal obesity, elevated triglycerides, reduced high-density lipoprotein, high blood pressure, increased fasting glucose, and hyperinsulinemia. These factors increase the risk of cardiovascular disease (CVD) and/or type 2 diabetes. Although the etiology of this syndrome is thought to stem from obesity and physical inactivity, the extent of interactions of the individual MetS components with one another remains poorly defined. Obesity, diabetes, hypogonadism, and specific hormone and metabolic profiles have been implicated in the pathophysiology of CVD. The evolving role of androgens in MetS and CVD is of paramount importance. Reduced androgen levels associated with hypogonadism or androgen deprivation therapy increase cardiovascular risk factors and produce marked adverse effects on cardiovascular function. MetS has been associated with hypogonadism and erectile dysfunction (ED), and MetS may be considered a risk factor for ED. It is suggested that MetS, diabetes, and CVD will increase in the upcoming decades. Thus, it is critically important to develop a better understanding of how obesity, diabetes and hypogonadism contribute to androgen deficiency and the various pathophysiologic states of vascular disease. In this review we discuss the current literature pertaining to androgen deficiency, MetS, and ED, because the relationship of these factors is of scientific and clinical importance. Specifically, we will focus on exploring the relationships between hypogonadism, obesity, MetS, and ED.
284 citations
TL;DR: This review considers what is known about renewal and proliferation of spermatogonia, how germ cells are organized in cellular associations constituting the cycle of the seminiferous epithelium, relative frequencies of cellular associations, durations of the cycle and sperMatogenesis, and measurement of daily sperm production.
Abstract: Understanding the dynamics of spermatogenesis is central to clinical andrology or to probing environmental effects on human testes. This review considers what is known about renewal and proliferation of spermatogonia, how germ cells are organized in cellular associations constituting the cycle of the seminiferous epithelium, relative frequencies of cellular associations, durations of the cycle of the seminiferous epithelium and spermatogenesis, and measurement of daily sperm production. Daily sperm production (DSP) per testis tends to decline with advancing age. Regardless of age, there is substantial loss of potential sperm from degeneration of spermatocytes, but not spermatids. DSP per gram testis parenchyma or DSP per testis cannot be predicted on the basis of testis size or age of a man. The review shows why our 1960s data base is neither robust nor precise and suggests how deficiencies might be rectified. New cellular associations should be defined, with none representing >15% of the cycle of the seminiferous epithelium. Then determine when Apale-spermatogonia become committed to proliferate or how many mitotic divisions occur thereafter. Restudy the duration of spermatogenesis because the accepted value might be in error by ∼6 days. Restudying human spermatogenesis will benefit clinicians, toxicologists, and epidemiologists probing testis function by direct evaluations or indirectly via evaluations of quantity and quality of sperm ejaculated. It also will benefit scientists interested in renewal and proliferation of spermatogonia, or a spermatogonium as a prototype stem cell.
269 citations
TL;DR: A new MetS/male infertility paradigm is proposed and additional studies specifically addressing the components of MetS and their impact on male reproduction will enhance the understanding of the underlying pathophysiology.
Abstract: Metabolic syndrome (MetS) is highly prevalent, affecting more than 47 million US residents. This condition is also multifaceted, potentially leading to significant disturbance of numerous physiologic processes. This review article evaluates the literature regarding metabolic syndrome and male reproductive health. Links between obesity, dyslipidemia, hypertension, and insulin resistance are each examined with regard to their associated detrimental effects on male fertility. At the end of this manuscript, we propose a new MetS/male infertility paradigm. Additional studies specifically addressing the components of MetS and their impact on male reproduction will enhance our understanding of the underlying pathophysiology. These studies may also help clarify the role for therapeutic intervention.
267 citations
TL;DR: It is suggested that androgen deficiency is associated with IR, T2D, MetS, and with increased deposition of visceral fat, which serves as an endocrine organ, producing inflammatory cytokines and thus promoting endothelial dysfunction and vascular disease.
Abstract: A considerable body of evidence exists suggesting a link among reduced testosterone plasma levels, type 2 diabetes (T2D), and insulin resistance (IR). Hypogonadal men are at higher risk for T2D. Here we evaluate the relationships between testosterone, metabolic syndrome (MetS), T2D, and IR and discuss the relationships among androgen deficiency and these factors, especially as it ultimately relates to the development of cardiovascular disease and erectile dysfunction (ED). Thus, a comprehensive literature search was carried out using PubMed, and relevant articles pertinent to androgen deficiency, T2D, IR, MetS, and ED were reviewed and discussed. Low testosterone precedes elevated fasting insulin, glucose, and hemoglobin A1c (HbA1C) values and may even predict the onset of diabetes. Treatment of prostate cancer patients with surgical or medical castration exacerbates IR and glycemic control, strengthening the link between testosterone deficiency and onset of T2D and IR. Androgen therapy of hypogonadal men improves insulin sensitivity, fasting glucose, and HbA1c levels. We suggest that androgen deficiency is associated with IR, T2D, MetS, and with increased deposition of visceral fat, which serves as an endocrine organ, producing inflammatory cytokines and thus promoting endothelial dysfunction and vascular disease.
240 citations
TL;DR: It is concluded that the enrichment and culture approach is highly useful for exploration of SSC expansion and indications that the system supports differentiation up to the level of postmeiotic germ cells are found.
Abstract: Isolation and culture of spermatogonial stem cells (SSCs) has become an approach to study the milieu and the factors controlling their expansion and differentiation. Traditional conventional cell culture does not mimic the complex situation in the seminiferous epithelium providing a basal, intraepithelial, and adluminal compartment to the developing male germ cells. SSCs are located in specific stem cell niches whose features and functional parameters are thus far poorly understood. It was the aim of this study to isolate SSCs and to explore their expansion and differentiation potential in a novel three-dimensional Soft-Agar-Culture-System (SACS). This system provides three-dimensional structural support and multiple options for manipulations through the addition of factors, cells, or other changes. The system has revolutionized research on blood stem cells by providing a tool for clonal analysis of expanding and differentiating blood cell lineages. In our studies, SSCs are enriched using Gfralpha-1 as a specific surface marker and magnetic-activated cell sorting as a separation approach. At termination of the culture, we determined the type and number of germ cells obtained after the first 24 hours of culture. We also determined cell types and numbers in expanding cell clones of differentiating germ cells during the subsequent 15 days of culture. We analyzed a supportive effect of somatic cell lineages added to the solid part of the culture system. We conclude that our enrichment and culture approach is highly useful for exploration of SSC expansion and have found indications that the system supports differentiation up to the level of postmeiotic germ cells.
139 citations
TL;DR: T administration had a beneficial effect on sexual dysfunction and symptoms of the metabolic syndrome in elderly men and the higher plasma levels of T generated with TU than with T gel were clearly more effective, indicating that there is a T dose-effect relationship.
Abstract: The objective of this study was to observe the dose-response effects of testosterone (T) treatment on symptoms of sexual dysfunction and the metabolic syndrome. Two cohorts of elderly men with late-onset hypogonadism were followed over 9 months. Group 1, consisting of 28 men (mean age, 61 years; mean T level, 2.07 +/- 0.50 ng/mL), received long-acting T undecanoate (TU; 1000 mg); group 2, composed of 27 men (mean age, 60 years; mean T level, 2.24 +/- 0.41 ng/mL), received T gel (50 mg/day) for 9 months. In patients treated with T gel, plasma T levels rose from 2.24 +/- 0.41 to 2.95 +/- 0.52 (statistically significant) at 3 months, 3.49 +/- 0.89 (statistically significant) at 6 months, and 3.80 +/- 0.73 ng/mL at 9 months (T level at 6 months was compared with T level at 3 months). With TU, plasma T levels rose from 2.08 +/- 0.56 to 4.81 +/- 0.83 (statistically significant) at 3 months, 5.29 +/- 0.91 at 6 months, and 5.40 +/- 0.77 ng/mL at 9 months. With TU, the plasma T levels were statistically significantly higher than with T gel With TU, there was a greater improvement in sexual symptoms and in symptoms of the metabolic syndrome. With both treatments, changes in waist circumference correlated with changes in total, low-density, and high-density lipoprotein cholesterol. Parameters of safety were not different between the 2 treatments. T administration had a beneficial effect on sexual dysfunction and symptoms of the metabolic syndrome in elderly men. The higher plasma levels of T generated with TU than with T gel were clearly more effective, indicating that there is a T dose-effect relationship.
136 citations
TL;DR: The normal development of male external genitalia and the prevalence and environmental risk factors related to hypospadias are reviewed and some of the recent laboratory findings that contribute to the current understanding of this disease are discussed.
Abstract: Hypospadias is one of the most common congenital anomalies in the United States, occurring in approximately 1 in 125 live male births. Embryological studies have demonstrated that, depending on where the urethral development arrests, the meatal opening can be anywhere along the shaft of the penis or, in more severe forms, within the scrotum or in the perineum. Currently, the only available treatment is surgery. If left uncorrected, especially in its severe form, there is risk of infertility and psychological effects, such as avoidance of intimate relationships. The cause of hypospadias is largely unknown; however, current epidemiology and laboratory studies have shed new light into the etiology of hypospadias. With recent advancements in molecular biology and microarray technology, it appears that hypospadias is potentially related to disrupted gene expression. Specifically, some of the environmental chemicals are acting as antiandrogens and interfere directly with the action of testosterone-related gene expression. In this paper, we briefly review the normal development of male external genitalia and the prevalence and environmental risk factors related to hypospadias. In addition, we discuss some of the recent laboratory findings that contribute to our current understanding of this disease.
123 citations
TL;DR: Long-term prospective studies of ADT are needed to determine the timing of onset of complications and to employ strategies to prevent them, and baseline and serial screening for fasting glucose and other cardiac risk factors in men receiving ADT is prudent.
Abstract: Prostate cancer (PCa) is the most common cancer in men. Androgen deprivation therapy (ADT) is used in the treatment of locally advanced and metastatic PCa. Although its use as an adjuvant therapy has resulted in improved survival in some patients, ADT has negative consequences. Complications like osteoporosis, sexual dysfunction, gynecomastia, and adverse body composition are well known. Recent studies have also found metabolic complications in these men. Studies show that short-term ADT (3-6 months) results in development of hyperinsulinemia without causing hyperglycemia. Studies of men undergoing long-term (>or=12 months) ADT reveal higher prevalence of diabetes and metabolic syndrome compared with controls. In addition, men undergoing ADT also experience higher cardiovascular mortality. Long-term prospective studies of ADT are needed to determine the timing of onset of these complications and to employ strategies to prevent them. In the meantime, baseline and serial screening for fasting glucose and other cardiac risk factors in men receiving ADT is prudent. In selected cases, glucose tolerance testing and cardiac evaluation may be required.
113 citations
TL;DR: The epididymal functions of transporting, concentrating, maturing, and storing sperm are important to male fertility and their absence or significant impairment can be a factor in male infertility.
Abstract: The epididymis consists of a single, highly coiled and convoluted tubule that Antoine De Graaf, the famous 17th-century anatomist, likened to a thread thickening to a string. The uncoiled tubule is several meters long and sperm in transit through it become functionally mature under the under the influence of the tubule lumen's microenvironment. The regulation of that microenvironment and the manner by which it influences sperm maturation have been the topic of investigation for many years, though the study of the human epididymis directly is fraught with problems related to sample availability and condition. Nevertheless, investigations using a variety of mammalian tissue sources, human included, have resulted in significant advances in our understanding of both the biology and pathology of the organ. The epididymal functions of transporting, concentrating, maturing, and storing sperm are important to male fertility and their absence or significant impairment can be a factor in male infertility.
TL;DR: The results obtained suggest that cytokines produced during the inflammatory process intensify the level of oxidative stress caused by leukocytes, which may have serious consequences for sperm membrane integrity.
Abstract: We have examined the effect of white blood cells (WBCs), various proinflammatory cytokines, or a combination of the two on the peroxidation of human sperm membrane lipids in in vitro conditions. Six recombinant cytokines, such as interleukin-1beta (IL-1beta), IL-6, IL-8, IL-12, IL-18, and tumor necrosis factor alpha (TNF-alpha), used singly or in combinations, were analyzed. WBCs were isolated from the whole heparinized blood using a density gradient technique (Histopaque 1.077). Spermatozoa were isolated from semen samples with normal sperm parameters by both the swim-up technique (swim-up fraction) and by a discontinuous Percoll gradient centrifugation (90% and 47% Percoll fractions). Peroxidative damage to sperm membrane lipids was assessed by determining the concentration of malondialdehyde (MDA) in lysates of spermatozoa using high-performance liquid chromatography (HPLC). There were no statistically significant differences in MDA concentrations between sperm fractions incubated with cytokines and respective controls (spermatozoa alone). In spermatozoa isolated by the swim-up technique, the MDA level was significantly higher only after incubation with IL-6 and IL-8 plus WBCs when compared to sperm incubated with leukocytes alone (0.62 +/- 0.21 micromol/L and 0.42 +/- 0.22 micromol/L, respectively; P < .05). In spermatozoa recovered from the 47% Percoll, only a combination of IL-12 and IL-18 used together with WBCs was linked with a significant increase in MDA concentration (from 0.41 +/- 0.13 micromol/L to 0.65 +/- 0.19 micromol/L; P < .05). The results obtained suggest that cytokines produced during the inflammatory process intensify the level of oxidative stress caused by leukocytes, which may have serious consequences for sperm membrane integrity.
TL;DR: This review highlights the relationship of mutations in the CFTR gene with CBAVD and CAUV, a genital form of cystic fibrosis that is responsible for 2%-6% of male infertility.
Abstract: A qualitative diagnosis of infertility requires attention to male and female physical abnormalities including endocrine anomalies and genetic conditions that interfere with reproduction. Many genes are likely to be involved in the complex process of reproduction. Congenital bilateral absence of the vas deferens (CBAVD) is a genital form of cystic fibrosis (CF) that is responsible for 2%-6% of male infertility. The incidence of CF varies in different populations; therefore, the incidence of CBAVD will also vary in different populations. The spectrum and distribution of cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations differ between CBAVD and CF patients and are comparable to control individuals. Combinations of particular alleles at several polymorphic loci yield insufficient functional CFTR protein. CFTR mutations are also associated with congenital absence of the uterus and vagina (CAUV). Females with CF are found to be less fertile than normal healthy women. Because of techniques such as intracytoplasmic sperm injection (ICSI), CBAVD patients are now able to father children. Such couples, however, have an increased risk of having a child with cystic fibrosis, and therefore genetic testing and counseling should be provided. Around 10% of obstructive azoospermia is congenital and due to mutations in the CF gene. This review highlights the relationship of mutations in the CFTR gene with CBAVD and CAUV.
TL;DR: In this study, certain enzymes in ram semen involved in reactive oxygen species elimination and their changes during the cryopreservation process were characterized in order to investigate the hypothesis that the antioxidant defense system is involved in the maintenance of frozen sperm quality.
Abstract: In this study, certain enzymes in ram semen involved in reactive oxygen species elimination and their changes during the cryopreservation process were characterized in order to investigate the hypothesis that the antioxidant defense system is involved in the maintenance of frozen sperm quality. Glutathione reductase (GR), glutathione peroxidase (GPx), and superoxide dismutase (SOD) activities were quantified in ram sperm samples subjected to cooling and freezing/thawing processes. In addition, their distribution on the sperm surface and the changes due to cryoinjury were determined by indirect immunofluorescence. SOD showed the highest antioxidant activity, which was also twice as high in fresh and cooled samples as in frozen/thawed ones. Enzymatic activity of GPx and GR showed no significant change throughout the freezing process. Seminal plasma proteins (SPPs) added alone or with other compounds showed a protective effect and accounted for an increase in the sperm quality parameters and enzyme activity levels not only in the fresh sample but also after cooling and freezing/thawing. These antioxidant enzymes were distributed over several sperm regions, and we were able to define several subpopulations according to the obtained sperm immunofluorescence patterns. The sperm membrane distribution of SOD, GPx, and GR changed considerably during cryopreservation, and the type and percentage of the immunofluorescence patterns found in fresh samples were severely modified. This remodeling was strongly affected by the use of different cryoprotectants. The mixture of SPPs, oleic/linoleic acids, and vitamin E was able to partly maintain and recover the fresh enzyme distribution, particularly of SOD.
TL;DR: In this article, the role of gonadal steroids in systemic antioxidant regulation was investigated in post-surgery hypopituitaric patients, and the results indicated that hypogonadism could represent a condition of oxidative stress, in turn related with augmented cardiovascular risk.
Abstract: Oxidative stress is involved both in metabolic syndrome and male infertility. Hypogonadism is also associated with increased risk for cardiovascular disease. To investigate the role of gonadal steroids in systemic antioxidant regulation, we determined plasma CoenzymeQ10 (CoQ10) and total antioxidant capacity (TAC) in postsurgical hypopituitaric patients. Twenty-six patients aged 28–55 years were studied 6–12 months after surgery. CoQ10 levels were measured by high-performance liquid chromatography and TAC by spectroscopy with the use of the mioglobin-H2O2 system, which, in interacting with chromogen 2,2I-azinobis-(3-ethylbenzothiazoline-6-sulfonate), generates a radical after a latency time (LAG) that is proportional to antioxidant content. Sixteen patients presented low testosterone values; in 10 patients hypogonadism was isolated, and in 6 patients hypothyroidism also was present. CoQ10 levels were significantly lower in isolated hypogonadism than in normogonadism. Testosterone treatment, performed in those patients with isolated hypogonadism, induced a significant enhancement both in CoQ10 level and LAG. CoQ10 and LAG values correlated significantly, suggesting an interrelationship between different antioxidants. Our data suggest that hypogonadism could represent a condition of oxidative stress, in turn related with augmented cardiovascular risk.
TL;DR: Using this germ cell model, the data suggest that changes in cellular oxidation-reduction (redox) homeostasis in the germline can accompany MEHP exposure, disrupting mitochondrial antioxidant defenses, despite absence of phthalate-induced apoptosis.
Abstract: Mono-(2-ethylhexyl) phthalate (MEHP), the biologically active metabolite of the plasticizer di-(2-ethylhexyl) phthalate, is a member of a class of chemical compounds with known adverse effects on the male reproductive system. Recent studies showed that oxidative stress and mitochondrial dysfunction in germ cells may contribute to phthalate-induced disruption of spermatogenesis. To determine whether the redox-protein mitochondrial thioredoxin-dependent peroxidase, peroxiredoxin 3 (Prx3), may be a component of germ cell homeostasis mechanisms, this study first examined the physiologic relevance of Prx3 in the rodent testis by determining its cell-specific expression. Our findings show that prx3 mRNA is expressed in a developmental, cell-specific manner in rat Leydig cells, Sertoli cells, and germ cells; among mouse germ cells, prx3 expression was highest in spermatocytes, findings consistent with those in rat. In mouse meiotic spermatocytes, Prx3 was strikingly localized at the nuclear perimeter and cytoplasm, findings suggestive of a direct role for Prx3 in determining spermatocyte response to toxicants. To better define the mechanisms involved in male germ cell dysfunction following phthalate exposure, an immortalized mouse spermatocyte-derived germ cell line, GC-2spd(ts), was exposed to MEHP (24 hours; 100 and 200 microM). We determined whether Prx3 and cyclooxygenase-2 (COX-2), pivotal proteins involved in oxidative stress responses in spatially restricted subcellular domains, were affected. Mitochondrial Prx3 and mitochondrial and cytosolic COX-2 significantly increased following 200 microM MEHP treatment; proliferation was inhibited without inducing cell death. Using this germ cell model, the data suggest that changes in cellular oxidation-reduction (redox) homeostasis in the germline can accompany MEHP exposure, disrupting mitochondrial antioxidant defenses, despite absence of phthalate-induced apoptosis.
TL;DR: The results suggest that increased oxidative damage might be a factor for hyperviscosity of seminal plasma in infertile males.
Abstract: Increased oxidative damage has been suggested to play an important role in the viscosity changes of blood. However, changes in levels of oxidative damage products in semen and their relationship to seminal fluid viscosity are unknown. The aim of our study was to investigate whether oxidative damage was associated with seminal plasma viscosity in infertile subjects. The levels of malondialdehyde, and protein carbonyls were measured in sperm and seminal plasma from 102 individuals, including 60 infertile patients. Seminal fluid viscosity and semen viscosity were studied by use of capillary viscometer and glass pipettes, respectively. Significantly higher levels of oxidative stress and damage markers were found in subfertile subjects compared with the control subjects. The seminal fluid viscosities of patients were found to be significantly higher, although all of the control and patient subjects had normal viscoelasticity when semen samples were assessed according to World Health Organization guidelines. From Pearson correlation analysis, there were significant positive correlations between seminal fluid viscosity and seminal malondialdehyde and carbonyl levels in infertile males (r = .676, P < .01; r = .276, P < .05, respectively). Our results suggest that increased oxidative damage might be a factor for hyperviscosity of seminal plasma in infertile males.
TL;DR: Age-specific reference ranges for serum DHEAS and testosterone levels for men are established and a better concordance with original data is possible because no distribution assumption is required and the robustness against outliers is given.
Abstract: Dehydroepiandrosterone (DHEA) is the main adrenal androgen, which mostly exists in a sulfated version (DHEAS). Both DHEA and DHEAS are metabolic intermediates in the biosynthesis of the male sex hormone testosterone. In men, testosterone is involved in the regulation of fertility, libido, and muscle mass and is valuable for the assessment of gonadal, adrenal, and pituitary function and for the diagnosis of hypogonadism. The objective of the present study was to calculate age-specific reference ranges for serum DHEAS and serum testosterone using 1) linear regression and the mean ± 1.96 standard deviation concept and 2) quantile regression. From the cross-sectional Study of Health in Pomerania a total of 1078 men aged 20–79 years were included in the analyses. Serum DHEAS and testosterone levels were quantified using IMMULITE 2500 immunoassays. Linear and quantile regression were performed to calculate age-specific reference ranges. Both statistical methods generated different results: The reference ranges based on linear regression identified 17 men (1.6%) with DHEAS levels and 45 men (4.2%) with serum testosterone levels outside the reference range. Using quantile regression, 54 men (5.0%) and 50 men (4.6%) with serum DHEAS and testosterone levels outside the range were detected, respectively. The present study established age-specific reference ranges for serum DHEAS and testosterone levels for men. Quantile regression should be preferred to calculate reference ranges; a better concordance with original data is possible because no distribution assumption is required and the robustness against outliers is given.
TL;DR: Both animal and clinical studies indicate that testosterone replacement therapy improves both erectile function and the response to PDE-5 inhibitors in patients with ED and hypogonadism, and suggest that testosterone therapy may be a valuable option for an increasing number of affected men.
Abstract: Aging is associated with a decline in several important health factors in men, including libido. Serum testosterone concentrations also decrease with age, and many age-related clinical features are closely associated with androgen deficiency, including erectile function (ED). Approximately 70% of ED is of organic origin, with the major risk factors being diabetes mellitus, hypercholesterolemia, smoking and chronic medical illnesses. These are also established risk factors for atherosclerosis, which is the predominant predisposing factor of vasculogenic ED. The introduction of phosphodiasterase-5 (PDE-5) inhibitors for the treatment of ED made a significant impact both in terms of clinical efficacy, and increasing the awareness of the condition. In spite of this, some patients fail to respond to PDE-5 inhibitors alone. Both animal and clinical studies indicate that testosterone therapy improves both erectile function and the response to PDE-5 inhibitors in patients with ED and hypogonadism. Indeed, interventional studies demonstrate that testosterone replacement therapy improves erectile function in hypogonadal men who have previously failed to respond to PDE-5 inhibitors alone. Furthermore, it has been demonstrated that the full therapeutic potential of PDE5 inhibitors will only become manifest in a eugonadal state. Recent studies have demonstrated a close relationship between testosterone and ED and suggest that testosterone therapy may be a valuable option for an increasing number of affected men. European guidelines recommend that all men presenting with ED should have their testosterone concentrations measured.
TL;DR: Atorvastatin, but not elocalcitol, ameliorates sildenafil-induced penile erections in SHR, likely by interfering with RhoA/ROCK signaling within the penis.
Abstract: Spontaneously hypertensive rats (SHR) are characterized by impaired erectile function and overactivity of the procontractile RhoA/Rho-associated, coiled-coil-containing protein kinase (RhoA/ROCK) pathway, as compared with their normotensive counterpart, Wistar-Kyoto rats. By measuring the intracavernous pressure:mean arterial pressure (ICP:MAP) ratio after electrostimulation of the cavernous nerve, we confirmed these findings and showed that responsiveness to sildenafil (25 mg/kg by oral gavage) also is hampered in SHR. A 2-week treatment with atorvastatin (5 and 30 mg/kg) improved the sildenafil-induced ICP:MAP increase and normalized RhoA and ROCK2 overexpression in SHR corpora cavernosa (CC). Conversely, other genes, neuronal nitric oxide synthase (NOS), endothelial NOS, and phosphodiesterase 5, were unaffected. In human fetal smooth muscle cells derived from CC (hfPSMC), atorvastatin inhibited RhoA membrane translocation and ROCK activity, as well as RhoA-dependent biologic functions like cell migration and cell proliferation. Atorvastatin's effect on migration was rescued in a dose-dependent manner by geranylgeranyl pyrophosphate, suggesting the involvement of RhoA geranylgeranylation. In hfPSMC, atorvastatin decreased the expression of RhoA-dependent genes such as ROCK2, desmin, alpha-smooth muscle actin, SM22alpha, and myocardin. In contrast to atorvastatin, elocalcitol, a vitamin D analog that also interferes with RhoA activation in SHR bladder, was unable to restore penile responsiveness to sildenafil. In conclusion, atorvastatin, but not elocalcitol, ameliorates sildenafil-induced penile erections in SHR, likely by interfering with RhoA/ROCK signaling within the penis.
TL;DR: The relationship between adenosine triphosphate (ATP) production (oxidative phosphorylation and glycolysis) and fertility of bovine spermatozoa is investigated, the proportion of oxygen consumption devoted to proton leak and that due to nonmitochondrial processes are determined, and whether freeze/thawing affects sperm oxygen consumption is discovered.
Abstract: This article's objectives are to investigate the relationship between adenosine triphosphate (ATP) production (oxidative phosphorylation and glycolysis) and fertility of bovine spermatozoa, determine the proportion of oxygen consumption devoted to proton leak and that due to nonmitochondrial processes, and discover whether freeze/thawing affects sperm oxygen consumption. Oxygen consumption of bovine spermatozoa was measured using a standard Clark electrode and, for the first time, in an Oxygen Biosensor System (OBS). Total ATP formation by bovine spermatozoa was calculated from the oxygen consumption and lactate production (glycolysis) by the same spermatozoa sample. ATP production varied from 1.99 to 8.09 μmol ATP per 10 8 spermatozoa per hour; glycolysis accounted for 16% to 38% of ATP. Nonmitochondrial oxygen consumption could not be detected in bovine spermatozoa using these methods. A significant proportion (16%-43%) of oxygen consumption was insensitive to oligomycin and was due to "proton leak." There was no significant difference between oxygen consumption of frozen/thawed and fresh spermatozoa for 2 of the 3 bulls tested. However, oxygen consumption of frozen/thawed spermatozoa was significantly higher (P <.05) than fresh spermatozoa for the third bull. When ZO 2 of frozen/thawed spermatozoa from 20 bulls was compared with their 49 day nonreturn rates (NRRs), oxygen consumption was correlated positively with NRR (ie, fresh spermatozoa with a higher ZO 2 were more fertile). Moreover, total ATP production correlated with NNR better than ZO 2 . Bulls with a lower NRR produce spermatozoa that are susceptible to damage during the freeze/thawing process, causing an increase in ZO 2 , possibly due to mitochondrial membrane damage resulting in more energy being expended in maintaining the proton gradient, or capacitation-like changes causing hyperactivation. Oxygen consumption measured in the OBS may be useful in assessing bovine sperm fertility.
TL;DR: The persistence of the elevation in preimplantation loss 9 weeks after BEP treatment suggests that spermatogonia are affected, and the effects of BEP on male reproductive function, fertility, and progeny outcome are investigated using a rat model.
Abstract: Testicular cancer is the most common cancer among young men of reproductive age. A regimen of bleomycin, etoposide, and cisplatin (BEP regimen) is the standard chemotherapy for testicular cancer. BEP has adverse effects on spermatogenic function that pose a long-term reproductive health risk to cancer survivors and their progeny. Using a rat model, we investigated the persistence of the effects of BEP on male reproductive function, fertility, and progeny outcome. Adult male Sprague-Dawley rats received a BEP regimen mimicking human clinical exposure (three 21-day cycles of etoposide and cisplatin on days 1-5 and bleomycin on days 2, 9, and 16, or vehicle). Reproductive and progeny outcome parameters were assessed at the end of BEP treatment and up to 9 weeks post-treatment, at 3-week intervals. BEP treatment reduced testicular weights and impaired spermatogenesis, characterized by abnormal testis histology and germ cell depletion. Germ cell apoptosis increased at least 3-fold in BEP-treated rats compared with controls at the end of treatment; 9 weeks posttreatment, germ cell apoptosis in BEP-treated rats did not differ from controls. BEP-exposed males were fertile; a decrease in litter size and an increase in preimplantation and postimplantation losses were observed. Preimplantation loss remained elevated in litters sired by BEP-treated males up to 9 weeks posttreatment; however, neither postimplantation loss nor litter sizes differed from controls. Thus, both germ cell apoptosis and the postimplantation loss induced by BEP treatment were reversible. The persistence of the elevation in preimplantation loss 9 weeks after BEP treatment suggests that spermatogonia are affected.
TL;DR: The results strengthen the hypothesis of possible digenic inheritance in some patients with KS and extend previous reports demonstrating that PROKR2 plays a role in the etiology of this syndrome.
Abstract: Kallmann syndrome (KS) is characterized by the association of hypogonadotropic hypogonadism and anosmia or hyposmia. To date, 4 different genes have been identified as responsible for the presence of KS; however, in many cases no mutations have been found in any of these genes. Herein, we report the molecular findings regarding the analysis of fibroblast growth factor receptor 1 (FGFR1), prokineticin receptor 2 (PROKR2), and prokineticin (PROK2) in patients with KS. Twenty-four patients with KS were studied in whom mutations in KAL1 had been investigated previously. Polymerase chain reaction products from FGFR1, PROKR2, and PROK2 were sequenced and mutations were sought in the open reading frame of the 3 genes. Two patients presented a heterozygous T-to-G transversion in exon 2 (c.518T>G) of the PROKR2, which results in a leucine-to-arginine substitution at codon 173. Our results strengthen the hypothesis of possible digenic inheritance in some patients with KS. Likewise, our data extend previous reports demonstrating that PROKR2 plays a role in the etiology of this syndrome.
TL;DR: Results demonstrated that there are factors released from fragmented spermatozoa capable of inducing DNA fragmentation in intact sperm that may compromise, to some extent, birth rates after ICSI.
Abstract: Endogenous nucleases in mouse sperm can be activated by freeze-thawing the spermatozoa in media without cryoprotection and cleaving spermatozoa DNA. The role of sperm chromatin integrity during intracytoplasmic sperm injection (ICSI) is of critical importance. We analyzed in the B6D2 mouse the proportion of DNA-fragmented spermatozoa (DFS) produced by incubation in conditioned medium (CM) generated by freeze-thawing sperm in the absence of cryoprotection. We then examined the subsequent development, implantation, and offspring obtained after ICSI with incubated spermatozoa. When fresh sperm cells were incubated for 90 minutes in this CM, a significant increase in the amount of DFS was detected by the terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling assay (27% vs 4.5% in fresh sperm). After ICSI of fresh and incubated spermatozoa, embryos were cultured in vitro to either the 2-cell or blastocyst stage before they were transferred into pseudopregnant CD1 females. On day 14, recipients were sacrificed, and implantation rates, estimated as the number of live fetuses plus resorptions, were determined. When ICSI was performed with sperm incubated in CM, no effects on fertilization, embryo cleavage, blastocyst rate, or blastocyst morphology were detected; however, the quality of the embryos was affected because the total implantation rate decreased significantly (P < .05) when 2-cell embryos or blastocysts were transferred. Independently of sperm pretreatment, in vitro cultures significantly affected the percentage of live fetuses present on day 14 of pregnancy. These results demonstrated that there are factors released from fragmented spermatozoa capable of inducing DNA fragmentation in intact sperm that may compromise, to some extent, birth rates after ICSI.
TL;DR: The results indicate that ESP is a human alloantigen involved in sperm-egg binding and fusion, and may offer opportunities for differential diagnosis of immune infertility.
Abstract: The equatorial segment of the sperm head is known to play a role in fertilization; however, the specific sperm molecules contributing to the integrity of the equatorial segment and in binding and fusion at the oolemma remain incomplete Moreover, identification of molecular mediators of fertilization that are also immunogenic in humans is predicted to advance both the diagnosis and treatment of immune infertility We previously reported the cloning of Equatorial Segment Protein (ESP), a protein localized to the equatorial segment of ejaculated human sperm ESP is a biomarker for a subcompartment of the acrosomal matrix that can be traced through all stages of acrosome biogenesis (Wolkowicz et al, 2003) In the present study, ESP immunoreacted on Western blots with 4 (27%) of 15 antisperm antibody (ASA)-positive serum samples from infertile male patients and 2 (40%) of 5 ASA-positive female sera Immunofluorescent studies revealed ESP in the equatorial segment of 89% of acrosome-reacted sperm ESP persisted as a defined equatorial segment band on 100% of sperm tightly bound to the oolemma of hamster eggs Antisera to recombinant human ESP inhibited both oolemmal binding and fusion of human sperm in the hamster egg penetration assay The results indicate that ESP is a human alloantigen involved in sperm-egg binding and fusion Defined recombinant sperm immunogens, such as ESP, may offer opportunities for differential diagnosis of immune infertility
TL;DR: The DNA fragmentation index (DFI) is higher in semen from men with SCI vs controls but does not seem to be due to prolonged anejaculation or to the proximate conditions of necrospermia or leukocytospermia.
Abstract: Semen from men with spinal cord injuries (SCI) and control subjects was investigated for sperm DNA damage using the sperm chromatin structure assay. Three experiments were performed. In experiment 1, the DNA fragmentation index (DFI) was compared in semen from SCI subjects and control subjects. In experiment 2, the % DFI was determined in repeated ejaculations to examine the effect of anejaculation on DFI. In experiment 3, the DFI was determined in neat vs processed semen to examine the effect of necrospermia or leukocytospermia on DFI. The results of experiment 1 showed a significantly higher mean (+/- SEM) DFI in the semen of SCI subjects (65.2% +/- 6.6%; range, 42.3%-90.8%) compared with control subjects (15.4% +/- 2.9%; range, 5.4%-33.5%; P < .001). In experiment 2, there was a high correlation between the DFIs obtained in the first semen specimens and the DFIs obtained 3 days later in semen of the same SCI subjects (r(s) = .94; P < .02). In experiment 3, the results showed no significant difference between mean DFI in aliquots of neat semen (79.3% +/- 9.9%) vs matched aliquots of semen processed to remove dead sperm and leukocytes in SCI subjects (75.2% +/- 16.1%). The DFI is higher in semen from men with SCI vs controls. The cause of this condition is unknown but does not seem to be due to prolonged anejaculation or to the proximate conditions of necrospermia or leukocytospermia. The relevance of these findings to fertility outcomes with SCI male partners remains to be determined.
TL;DR: The canine PMDS phenotype and clinical sequelae are described in detail and findings in this model could enable insights to be garnered from correlation of detailed clinical descriptions with molecular defects, which are not otherwise possible in the human syndrome.
Abstract: Mullerian inhibiting substance (MIS), a secreted glycoprotein in the transforming growth factor-beta family of growth factors, mediates regression of the Mullerian ducts during embryonic sex differentiation in males. In persistent Mullerian duct syndrome (PMDS), rather than undergoing involution, the Mullerian ducts persist in males, giving rise to the uterus, fallopian tubes, and upper vagina. Genetic defects in MIS or its receptor (MISRII) have been identified in patients with PMDS. The phenotype in the canine model of PMDS derived from the miniature schnauzer breed is strikingly similar to that of human patients. In this model, PMDS is inherited as a sex-limited autosomal recessive trait. Previous studies indicated that a defect in the MIS receptor or its downstream signaling pathway was likely to be causative of the canine syndrome. In this study, the canine PMDS phenotype and clinical sequelae are described in detail. Affected and unaffected members of this pedigree are genotyped, identifying a single base pair substitution in MISRII that introduces a stop codon in exon 3. The homozygous mutation terminates translation at 80 amino acids, eliminating much of the extracellular domain and the entire transmembrane and intracellular signaling domains. Findings in this model could enable insights to be garnered from correlation of detailed clinical descriptions with molecular defects, which are not otherwise possible in the human syndrome.
TL;DR: It is shown that TSN also binds to the microRNA miR-122a, complementary to a sequence in the 3' untranslated region of the transition protein 2 mRNA, suggesting an additional posttranscriptional function for TSN.
Abstract: Translin (TSN), also known as testis-brain RNA-binding protein, is proposed to bind to breakpoint junctions at chromosomal translocations in the nucleus and to specific RNAs in the cytoplasm. In germ cells of the mouse testis, it recognizes target mRNAs transcribed by the transcription factor CREM-tau in spermatids, specific meiotically expressed mRNAs, and a noncoding RNA that encodes piRNAs. Here we show that TSN also binds to the microRNA miR-122a. MiR-122a is expressed in late-stage germ cells and is complementary to a sequence in the 3' untranslated region of the transition protein 2 mRNA. The binding of TSN to miR-122a increases its in vivo stability, suggesting an additional posttranscriptional function for TSN.
TL;DR: The present review focuses on all of the aspects of male infertility treatment by hormone supplementation, aiming to improve mainly endogenous follicle-stimulating hormone and/or androgen levels and subsequent spermatogenesis.
Abstract: Approximately 50% of infertility issues are attributable to male factors. A number of different factors may result in similar reductions of sperm count or motility and affect sperm morphology. Not only is the etiology of male infertility difficult to understand, but it is equally challenging to treat male infertility because of its etiological heterogeneity. Because of complex and incomplete knowledge of the underlying causes, most infertile men are described as idiopathically oligozoospermic and/or asthenozoospermic. Different hormonal treatments have been attempted, aiming to improve mainly endogenous follicle-stimulating hormone and/or androgen levels and subsequent spermatogenesis. Various studies have tried to treat infertility through natural pregnancies or increased sperm retrieval for in vitro fertilization techniques, or by treating spermatozoa in vitro to improve its fertilizing potential. The present review focuses on all of the aspects of male infertility treatment by hormone supplementation.
TL;DR: It is suggested that rat sperm have unique properties that need to be considered during centrifugation, Percoll gradient separation, and pipetting procedures.
Abstract: The objective of this study was to determine the effects of various physical interventions such as centrifugation regimes, Percoll gradient separation, and repeated pipetting on various viability parameters of epididymal sperm of Fischer 344 (F-344) and Sprague-Dawley (SD) rat strains. Three experiments were conducted. In experiment 1, sperm motility and acrosomal and membrane integrity were compared after exposing sperm samples to 200, 400, 600, and 800 x g centrifugal forces for 5, 10, or 15 minutes. In experiment 2, sperm motility and acrosomal and membrane integrity were compared after passing them through a Percoll separation using centrifugal forces of 600, 800, 1000, and 1200 x g for either 15 or 30 minutes. In experiment 3, the effect of repeated pipetting (2, 4, 6, 8, and 10 times) on motility and membrane integrity of rat sperm was compared with that on mouse, ram, bull, and boar sperm. The results revealed that both F-344 and SD rat sperm motility and membrane integrity were significantly affected by centrifugation (P .05). Sperm from SD rats also had higher motility and membrane integrity loss than did sperm from F-344 rats after centrifugation and pipetting (P .05). Repeated pipetting had a dramatic adverse effect on both rat and mouse sperm motility (P .05). These data suggest that rat sperm have unique properties that need to be considered during centrifugation, Percoll gradient separation, and pipetting procedures.