Showing papers in "Journal of Andrology in 1985"

Testicular size: the effects of aging, malnutrition, and illness.

Abstract: Paired testicular volumes and weights, as well as age, height, and weight, were recorded from a series of 1056 consecutive necropsies on adult males ranging in age from 18 to 96 years. These data were analyzed to examine the effects of age, nutritional state (standardized body weight), and illness on testicular size. Testicular volume and weight were related by a constant density of 1.038 g/ml, regardless of testicular size, age or illness. Mean testicular volume was correlated with height (r = 0.470), weight (r = 0.504), body surface area (r = 0.549) and standardized body weight (r = 0.152). Advancing age, malnutrition, alcoholism, malignancy, and a chronic, terminal illness were each individual risk factors for reduced testicular size, whereas diabetes, narcotic or other drug usage, and pelvic injury were not associated with reduced testicular volume. Since advancing age, reduced standardized body weight, and some disease states were all associated with diminution of testicular size, the interaction of age, malnutrition, and illness on testicular size were examined by statistical modeling, using multivariate logistic regression and covariance analysis. The associations of alcoholism, malignancy, and chronic, terminal illness with decreased testicular volume were independent of aging or nutritional state. The effects of chronic, terminal illness were mostly explained by the concurrent effects of reductions in standardized body weight (malnutrition). After exclusion of men with diseases shown to be associated with decreased testicular size, he specific effects of age alone demonstrated a reduction in testicular volume only in the 8th decade of life.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of white blood cells on the in vitro penetration of zona-free hamster eggs by human spermatozoa.

Abstract: The presence of white blood cells in semen has been associated with male infertility. Previous studies indicate that pyospermia occurs in conjunction with decreases in sperm motility, number of normal sperm forms, and penetration rates in the zona-free hamster egg sperm penetration assay. We have evaluated the relationship of seminal white blood cells and sperm function, as reflected in the zona-free hamster egg penetration assay, and have investigated the possible mode of action of the white cells. Egg penetration rates decreased when white blood cells from fertile or potentially fertile donors were added to their sperm suspensions prior to preincubation and at insemination in the in vitro assay. Zona-free hamster egg penetration assay results were also inhibited when the supernatant from white blood cells incubated in Biggers, Whitten, and Whittingham (BWW) medium overnight were introduced to sperm-oocyte suspensions at insemination. Conversely, egg penetration rates were enhanced in samples from hypofertile individuals when white blood cell concentrations in the semen or WBC/sperm ratios were reduced, either by physical removal or as a result of antibiotic therapy. The physical presence of leukocytes, and possibly, the extracellular release of lysosomal enzymes may be responsible for the inhibitory effects in vitro. Although the mechanism(s) by which white blood cells interfere with the fertilizing capacity of spermatozoa are not clear, it is quite obvious that their presence in the in vitro environment is undesirable and can mask an individual's actual fertilizing potential.

Congenital absence of the vasa deferentia presenting with infertility.

Abstract: Congenital absence of both vasa deferentia is not an infrequent cause of sterility. Between April 1975 and December 1981, 11 men out of a total of 749 presenting with infertility were diagnosed as having congenital absence of both vasa deferentia. Subsequent clinical investigations showed that FSH levels were within the normal range (2-10 mIU/ml), blood karyotype (XY) was normal, and testicular histology demonstrated normal spermatogenesis. Seminal volume was markedly reduced in nine patients (range 0.25-1.0 ml). In three out of four patients tested, seminal fructose was found to be completely absent. Of the 11 patients, eight subsequently had exploratory surgery. In four men, the whole epididymis was present on both sides, while the other four had varying parts of one or both epididymides absent. In six of the eight patients explored surgically, no trace of the vasa deferentia could be found, while one other patient had thin fibrous cords in the anatomical site of the vasa deferentia. A possible cause for the abnormality and the importance of seminal fructose estimation are discussed.

Localization of cellular retinol-binding protein and cellular retinoic acid-binding protein in the rat testis and epididymis.

Abstract: The distribution of cellular retinol-binding protein (CRBP) and cellular retinoic acid-binding protein (CRABP) in rat testis and epididymis was examined by the peroxidase-antiperoxidase immunolocalization technique. In the testis, cellular retinol-binding protein was localized exclusively in the Sertoli cells. Staining varied with the stages of the seminiferous epithelium cycle and was maximal prior to the maturation divisions. Cellular retinoic acid-binding protein was localized exclusively in the germinal cells in the adluminal compartment. The results suggest that retinoic acid may be the retinoid form used by the germinal cells, and that Sertoli cells may use the cellular retinol-binding protein to transfer retinol from the basal to the adluminal compartment. In the epididymis, cellular retinol-binding protein was localized in the cytoplasm and stereocilia of the principal cells in the proximal caput epididymidis, while cellular retinoic acid-binding protein was localized in the spermatozoa and the stereocilia of the principal cells throughout the epididymis and in the epithelial cells of the distal vas deferens. Sperm staining intensity decreased from the initial segment to the cauda. The presence of high levels of cellular retinol-binding protein in the epithelial cells and high levels of cellular retinoic acid-binding protein in the spermatozoa of the caput epididymidis, known to be involved in the synthesis and secretion of factors necessary for sperm maturation, suggests that vitamin A may have a role in this process.

In vitro differentiation of rat seminiferous tubular segments from defined stages of the epithelial cycle morphologic and immunolocalization analysis.

Abstract: Rat seminiferous tubule segments have been cultured in chemically defined medium (F12/DMEM 1:1) without added hormones or growth factors. The segments (1-2 mm) were isolated from defined stages of the cycle of the seminiferous epithelium (VIII and XII) by transillumination-assisted microdissection. The precise stages were examined by phase contrast microscopy of live cells squashed carefully out from the adjacent segments between glass slides. The squash technique was also used for a primary screening of the cultured tubules. Pachytene primary spermatocytes from stages VIII to XII of the cycle were able to complete meiotic divisions in vitro. From stage XII, they differentiated up to step 5 spermatids, expressed their specific antigens, and developed characteristic movement patterns of the flagellum and of the chromatoid body. Preleptotene and zygotene spermatocytes from the same cell association differentiated synchronously, as judged by chromosome morphology, characteristic chromosome rotation in zygotene and early pachytene, and by development of specific antigen expression. The elongation phase of spermiogenesis did not proceed normally in vitro. The rate of differentiation was the same as observed earlier in vivo. Earlier studies with [3H]thymidine labeling and autoradiography only permitted follow-up of the development of preleptotene spermatocytes. With the present method, all stages of spermatogenesis can be traced in culture with great accuracy in experiments relating to local regulation of spermatogenesis.

Acute experimental testicular torsion. No effect on the contralateral testis

Abstract: Other investigators have shown that chronic unilateral testicular torsion produces negative effects on the contralateral testis in experimental animals. In the present study, bilateral testicular weight and histology, and concentrations and motility of spermatozoa from the cauda epididymidis were studied after 0 to 4 hours of acute unilateral testicular torsion in the rat. The obstruction of blood flow by torsion was documented, as well as the presence or absence of return blood flow after the relief of torsion. The above mentioned parameters of testicular function were studied at 7, 30, and 60 days after relief of torsion. Ipsilateral testis weights and epididymal sperm concentrations and motility were significantly reduced by 1, 2, and 4 hours of torsion. The histology of torsioned testes was also severely altered, and no seminiferous epithelial repair was evident 60 days after torsion. Contralateral testicles were not affected by ipsilateral torsion of 1, 2, or 4 hours duration, despite the fact that the ipsilateral testis function was completely compromised by 2 and 4 hours of torsion. These results indicate that there would be no clinical benefit in removing the acutely torsioned testis of Sprague-Dawley rats since it poses no threat to the contralateral testis.

Stagnation of blood in the microcirculatory vessels in the testes of men with varicocele.

Abstract: This study reports on the stagnation of blood within the microcirculatory vessels of the testes of patients with varicocele. Both fine structural and quantitative studies were carried out on testicular biopsies from 14 men with varicocele and a control group of three men. Arterioles, capillaries, and venules were completely filled with blood in all affected testes. Enlarged pores were also noticed between the endothelial cells of these affected vessels. Lumen diameters of the arterioles were significantly decreased in the affected testis compared to controls. No change in the overall diameter of the arterioles and venules was noted. Significant thickening of the limiting membrane was also noted in the affected testis. It was concluded that the stagnation of blood in the microcirculatory vessels may cause local hypoxia and ischemia, which lead to spermatogenic disorders.

Lectin-binding pattern of bull testis and epididymis.

Abstract: Seven rhodamine-conjugated lectins (PNA, RCA I, SBA, Con A, WGA, UEA I, DBA) were used to study the distribution of glycoproteins in the testis and epididymis of immature, juvenile, and adult bulls. A marked change was found in the staining pattern of the lectins in the seminiferous tubules during acrosomal development, and the Sertoli cells seemed to have a cyclic affinity for some of the lectins. The distribution of lectin staining in six regions of the bull epididymis showed some typical differences that were associated with the secretory and absorptive functions of the organ. Region 1 was characterized by strong surface and villous staining and a patchy reaction in the principal cells. Regions 2 and 3 showed a strongly reactive apical Golgi zone and secretory material. In regions 4 and 5, the Golgi zone was subapical but strongly reactive with most lectins, while in region 6 a weakly reactive apical Golgi zone was found. During sexual maturation, an increasing number of basal cells with a strong affinity for some lectins was found at the periphery of the epithelium in regions 2 to 6. These regions also had lectin-stained material along the basal border of the principal cells. These findings suggest that the basal cells may be active in the digestion of absorbed material and that they derive from the principal cells, which may be active in transporting absorbed material to them. The staining pattern of the spermatozoa changed during their transit through the epididymis. The degenerating cells in the testis and epididymal tubules also showed an altered affinity for the lectins.

Regional differences in luminal fluid polypeptides of the rat testis and epididymis revealed by two-dimensional gel electrophoresis

Abstract: Luminal fluid samples were collected by micropuncture of the seminiferous tubule, rete testis, and defined levels of the epididymal tubule. After removal of spermatozoa by centrifugation, the supernatant fluids were analyzed by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) and an ultrasensitive silver staining procedure to define the sequential change in protein composition along the excurrent duct system. Fluid from each segment displayed a characteristic 2-D PAGE map composed of numerous polypeptides. Seminiferous tubule fluid contained a wide array of polypeptides, with most concentrated in the 45 Kd to 90 Kd range, but, in contrast, rete testis fluid lacked most of these polypeptides. The major complex of rete testis fluid comigrated with serum albumin and was present in all distal segments. Other major rete testis components were not noted distally. Fluid from the caput was characterized by new major components of 30 to 37 Kd, 28 to 30 Kd, 24 Kd, and 23 Kd, each of which consisted of multiple spots of apparent isoelectric variants; all except the 30 to 37 Kd complex were present in the fluid from more distal segments. Proceeding distally, there was a temporal appearance of new polypeptides, especially in the molecular weight range below 30 Kd. Two-dimensional PAGE analysis of detergent extracts of washed spermatozoa indicate that a specific subset of these fluid polypeptides are sperm associated.

Flow Cytometric DNA Analysis of Defined Stages of Rat Seminiferous Epithelial Cycle During In Vitro Differentiation

Abstract: The stages of the rat seminiferous epithelial cycle have been isolated for flow cytometric analysis of DNA and for culture, using transillumination-assisted microdissection. Precise stages have been identified by phase contrast microscopy of live cell squashes from adjacent segments. Each stage of the cycle showed a characteristic flow cytometric pattern with haploid (1C), diploid (2C) and tetraploid (4C) peaks. Stages I to VIII of the cycle showed an additional hypofluorescent (0.25-0.70C) peak due to a reduced dye-binding capacity of maturation phase-spermatids at steps 15 through 19. The appearance of the hypofluorescent haploid peak coincided with the second nucleoprotein transition at step 15 of spermiogenesis and the homogeneous condensation of the chromatin seen in electron microscopy. As a concomitant of the formation of disulphide bonds during epididymal maturation, the fluorescence intensity decreased further to reach a relative value of 0.07C in the cauda epididymidis. The constant 1C peak was raised by round and elongating spermatids (steps 1-14), 2C by spermatogonia, secondary spermatocytes and Sertoli cells, and the 4C peak by primary spermatocytes and spermatogonia at G2 or M phase of the mitotic cycle. The proportion of each peak accurately reflected the relative proportion of cells in most stages of the cycle when compared with morphometric measurements of histologic preparations. DNA flow cytometry is a suitable method for quantitative evaluation of cultured seminiferous tubule segment DNA. Although the relative yield of the meiotic reductive divisions in vitro is comparable with that observed in vivo, steps 9 and 15 of spermiogenesis involving nucleoprotein transitions and spermiation itself did not occur under the present culture conditions.

Response to acute hCG stimulation and steroidogenic potential of Leydig cell fibroblastic precursors in humans.

Abstract: The process of early testosterone (T) secretion and Leydig cell differentiation in humans was studied to explore the steroidogenic capacity of Leydig cell fibroblastic precursors. Seven cryptorchid boys received hCG prior to orchidopexy. Patients CP, PB, and MR received one injection of 1000 IU; patients JR and GG, three daily injections of 1000 IU, and patients MP and MM, five daily injections of 1000 IU. A testicular biopsy was obtained at the time of operation, 24 hours after the last injection. Serum T (ng/dl) before and after hCG stimulation and testicular T (ng/g) were determined by RIA. A control prepubertal testis (tumoral orchidectomy) was incubated in vitro and showed a time-dependent accumulation of T both in the medium and the testicular tissue. Testosterone released into the medium at 1, 2, and 4 hours was 0.76, 1.43, and 4.03 ng/ml, respectively. Tissue T at 0, 1, 2, and 4 hours was 9, 11, 16, and 24 ng/g, respectively. This indicates synthesis and secretion of T into the medium. Control testes showed abundant fibroblastic precursors with scanty cytoplasm, few organelles, heterochromatic nuclei, and minute nucleoli. No Leydig cells were present. After 1 day of hCG stimulation, numerous fibroblasts were activated, displaying enlarged cytoplasms with increased numbers of organelles, nuclei rich in euchromatin, and bigger nucleoli. No Leydig cells were present. Basal serum testosterone was 58.2 +/- 45.3 ng/dl and 87.3 +/- 42.0 after hCG administration, while testicular T was 974.0 +/- 686.0 ng/g (control prepubertal testicular T is 10-50 ng/g). After 3 days of hCG, activated fibroblasts increased and immature Leydig cells appeared. Basal serum T was 35.5 +/- 7.8 ng/dl and 394.0 +/- 24.0 after hCG stimulation, while testicular T rose to 2797.5 +/- 1222.6 ng/g. After 5 days, mature Leydig cells appeared for the first time. Serum T was 58 +/- 59.3 ng/dl (basal) and 641.5 +/- 390 ng/dl (after hCG); testicular T was 789 ng/g (patient MM did not have a value for testicular T). HCG induced numerous coated pits and endocytic vesicles in activated fibroblasts and young Leydig cells, suggesting receptor aggregation and internalization of hormone-receptor complexes. Peroxidase-antiperoxidase (PAP) localization of T was positive in peritubular fibroblasts and Leydig cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Changes in Serum Levels of LH, FSH, Prolactin, Testosterone, and Cortisol Associated with Season and Mating in Male Pygmy Goats

Abstract: Four male pygmy goats were used in a study designed to determine the effects of season on serum hormone (luteinizing hormone, follicle stimulating hormone, prolactin, testosterone, and cortisol) levels, testis size and libido, and the effects of mating on serum hormone profiles. Seasonal peaks were observed for prolactin in July, luteinizing hormone and follicle stimulating hormone in September, and testosterone in October. Luteinizing hormone peak frequency was greatest in September and was increased by mating activity in the months immediately preceding the breeding season. Scrotal circumference did not vary with season and libido showed no consistent seasonal pattern. Mating appeared to raise all hormone levels except during the months when these hormones were seasonally elevated. When episodic releases of luteinizing hormone occurred, they were associated with subsequent rises in serum testosterone levels. On some mating days, when episodic releases of luteinizing hormone were absent, changes in testosterone levels were highly correlated with changes in cortisol levels. It was concluded that both season and mating influence reproductive hormone levels in male pygmy goats.

Stimulation of Sperm Production by Human Chorionic Gonadotropin after Prolonged Gonadotropin Suppression in Normal Men

Abstract: The precise hormonal milieu required for quantitatively normal spermatogenesis in man is unclear. The authors previously have shown that both supraphysiologic dosages of human chorionic gonadotropin (hCG) and physiologic dosages of human luteinizing hormone (hLH) can reinitiate sperm production in short-term (four months) gonadotropin-suppressed normal men who have prepubertal FSH levels. To determine whether normal FSH levels were necessary to stimulate sperm production after a prolonged period of gonadotropin and testicular suppression, the authors administered hCG to four normal men whose endogenous gonadotropin levels and sperm production were suppressed by prolonged exogenous testosterone (T) administration. After a 3-month control period, all subjects received 200 mg of T enanthate intramuscularly (im) each week to suppress LH and FSH for a total of 9 months and until successive sperm concentrations (performed twice monthly) revealed azoospermia or severe oligozoospermia (mean sperm concentration less than 3 X 10(6) spermatozoa/ml) for 6 months. Then, while continuing the same dosage of T enanthate, all four men simultaneously received 5000 IU of hCG im three times weekly for 6 months, replacing LH-like activity and leaving FSH activity suppressed. The effect on sperm production of the selective FSH deficiency produced by hCG plus T administration after the period of prolonged gonadotropin suppression was determined. Exogenous T administration resulted in severe suppression of sperm concentrations from 79 +/- 7 X 10(6) spermatozoa/ml (mean +/- SEM) during the control period to 0.8 +/- 0.5 X 10(6)/ml after 12 weeks of T treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Dose-response studies on male reproductive parameters in dogs with nafarelin acetate, a potent LHRH agonist.

Abstract: Adult male beagle dogs were administered daily subcutaneous injections of either 05 or 20 micrograms/kg of a potent LHRH agonist, nafarelin acetate, for 44 days Although there was a rise in the circulating levels of the gonadotropins and of testosterone following the early injections of agonist, continued treatment caused a marked decline in acute response and basal levels of both LH and testosterone and smaller decreases in the acute FSH response The decline in LH and testosterone was accompanied by decreases in testicular volume, ejaculated sperm count, sperm motility, ejaculate volume, and duration of ejaculation The decline in these parameters was more rapid at 20 micrograms/kg than at 05 micrograms/kg The profile of responses to 20 micrograms/kg could be superimposed on that previously shown for the injection of 100 micrograms/kg At the end of treatment, prostate weights were 36% and 68% of vehicle-treated controls for high- and low-dose animals, respectively Spermatogenesis was absent in the testes of all agonist-treated animals Over the dose range tested, the dose-response on all parameters was characterized by a slower evolution to the same maximal effect, rather than by a partial effect If these data can be extrapolated to man, they would suggest that administration of higher dose levels of LHRH agonists than presently reported should be explored

Androgen receptor levels and androgen contents in the prostate lobes of intact and testosterone-treated Noble rats.

Abstract: Plasma testosterone (T) levels were correlated with androgen receptors, tissue content of T, and 5 alpha-dihydrotestosterone (DHT) in the three anatomically-discrete prostate lobes of intact and castrated Noble (Nb) rats bearing T-filled silastic capsules. Differences in androgen receptor content and tissue androgen levels were observed among the three prostatic lobes of intact Nb rats. Total (cytosolic and nuclear) androgen receptor levels were highest in the ventral prostate followed by the dorsolateral and anterior prostate lobes. In the ventral and anterior prostate, androgen receptors were found to be equally distributed between cytosols and nuclear extracts, whereas in the dorsolateral prostate, androgen receptors were predominantly nuclear (cytosolic: nuclear = 1.5). The ventral prostate had the highest total androgen content and DHT was the major tissue androgen in all three lobes. The ratio of tissue DHT:T varied among the lobes; the highest value was observed in the dorsolateral prostate. The higher proportions of nuclear androgen receptor, as well as the elevated tissue DHT:T found in the dorsolateral prostate compared to other lobes, suggest that differences in the androgen activation process may exist between the dorsolateral prostate and other prostatic lobes. Despite lower plasma and tissue T levels, the DHT content, weight and cytodifferentiation in all lobes of T-treated castrated rats closely approximated the situation found in intact animals. Total androgen receptor levels were, however, elevated in all prostatic lobes of T-treated, castrated rats as compared to intact controls. These increases were primarily attributed to the augmented levels of androgen receptor in the nuclear extracts of the three prostate lobes. Exposure of the prostate to a constant level of T, produced by silastic implantation, might be responsible for the higher total androgen receptor levels and enhanced nuclear androgen receptor retention found in the prostates of T-treated, castrated rats.

Effects of induced hypoprolactinemia on testicular function during gonadal maturation in the rat.

Abstract: We have evaluated the effects of hypoprolactinemia during gonadal maturation in the male rat. Intact 30-day-old rats were injected daily for 10 days with three different doses of bromocriptine (0.75, 1.5 or 3.0 mg/kg of body weight/day). At the end of the treatment period, the animals were sacrificed, serum was collected for prolactin (PRL), LH, and androgen measurements. Intratesticular testosterone and 5 alpha-androstanediol (androstanediol) were measured following celite column chromatography and a specific radioimmunoassay. In addition, the production of androgens by decapsulated testes and dispersed Leydig cells was also studied in vitro. Serum levels of PRL (9.4 +/- 1.9 ng/ml) were suppressed to undetectable levels in the three bromocriptine-treated groups, whereas LH levels were not altered. All three doses of bromocriptine markedly depressed serum testosterone (plus DHT) and androstanediol. Intra-testicular testosterone and androstanediol were diminished (25% and 35%, respectively, P less than 0.05) during hypoprolactinemia. Decapsulated testes and dispersed Leydig cells from bromocriptine-treated animals showed a significant reduction in the basal secretion of testosterone (plus DHT) and androstanediol, and in androgen responses to submaximal hCG stimulation. Maximal steroidogenic responses from bromocriptine-treated rats were similar to controls. The present findings show that, during puberty, bromocriptine influences testicular steroidogenesis, and these effects may be partly due to changes in PRL levels. A direct effect of this dopaminergic agonist on the male gonad cannot be completely ruled out.

The Origin of Some Acid Hydrolases of the Fluid of the Rat Cauda Epididymidis

Abstract: The activity of N-acetyl-beta-D-glucosaminidase (NAG, 60.1 units/mg protein) and of acid phosphatase (57.7 units/mg protein) in fluid from the cauda epididymidis formed without any contribution from the testis (fluid obtained from a perfused and isolated cauda epididymidis or from an epididymis whose corresponding efferent ducts had been ligated for 40 days) was significantly higher than the activity of these enzymes in normal fluid (39.6 and 41.2 units/mg protein, respectively). Arylsulphatase activity of the locally formed fluid (11.2 units/mg protein) was lower than that of normal fluid (74.1 units/mg protein). The rete testis fluid was relatively rich in arylsulphatase since the ratio of arylsulphatase to acid phosphatase activity was 17 times higher in this fluid than in locally formed fluid. It is concluded that the activities of NAG and acid phosphatase in normal fluid from the epididymis originate in the epididymal tissue, while most of the arylsulphatase activity comes from the testis.

Receptor‐mediated Endocytosis of Alpha2‐macroglobulin by Principal Cells in the Proximal Caput Epididymidis In Vivo

Abstract: Micropuncture techniques were used to study receptor-mediated endocytosis of alpha 2-macroglobulin bound to colloidal gold (alpha 2M-gold) by principal cells in the proximal caput epididymidis of control and efferent duct-ligated rats. The pathway of receptor-mediated endocytosis of alpha 2-macroglobulin-gold in vivo was similar to that which occurs in vitro. Alpha 2-macroglobulin-gold was taken up and internalized in coated pits and coated vesicles and was localized sequentially in uncoated vesicles (endosomes), tubular-vesicular structures, multivesicular bodies, and lysosomes. However, a 100-fold excess of alpha 2-macroglobulin did not displace the uptake of alpha 2-macroglobulin-gold in principal cells from control rats. In contrast, uptake of alpha 2-macroglobulin-gold by principal cells from efferent duct-ligated rats was six-fold greater than in control rats, and could be displaced to control levels by a 100-fold excess of alpha 2-macroglobulin. It is suggested that the inability of a 100-fold excess of alpha 2-macroglobulin to displace uptake of alpha 2-macroglobulin-gold in control rats was due to the normal saturation of apparent alpha 2-macroglobulin receptors on principal cells. The effect of efferent duct ligation was to remove the high levels of endogenous alpha 2-macroglobulin, which depleted the receptors of alpha 2-macroglobulin, thereby allowing a higher uptake of alpha 2-macroglobulin-gold in the efferent duct-ligated rats.

Testicular LH Receptors During Aging in Fisher 344 Rats

Abstract: Levels of serum LH, prolactin, testosterone, progesterone and 17-OH progesterone and the testicular concentration and total content of LH receptors were measured in 4-, 11-, 18-, and 27-month-old Fisher 344 rats. All 27-month-old rats had Leydig cell tumors. At first, testicular LH receptor levels decreased with age, but with the appearance of the testicular tumors, these levels increased dramatically. Serum prolactin levels fluctuated with age, but were significantly decreased in 27-month-old rats, as were serum LH levels. Serum testosterone levels decreased steadily with age, while the testosterone-LH receptor ratio remained constant until the appearance of the testicular tumors, after which the ratio decreased precipitously. Serum progesterone levels remained constant throughout the life of Fisher 344 rats until the appearance of testicular tumors, when they increased dramatically. Serum 17-OH progesterone levels were increased significantly at 11 and 27 months as compared to four months of age, but levels at 18 months were similar to those seen in the 4-month-old animals. Therefore, in aged Fisher 344 rats with spontaneous Leydig cell tumors, there is an alteration in the testicular testosterone synthesizing pathway at a step after progesterone.

Decreased fertility and motility of spermatozoa from rats immunized with a prealbumin epididymal-specific glycoprotein.

Abstract: This study investigated the effects on the progressive motility, zona-binding capacity, and fertility of spermatozoa from the cauda epididymidis of adult male rats that were actively immunized against an acidic glycoprotein secreted by the epididymis. The percentage of motile spermatozoa was less than 5% in nine of ten rats that received the epididymal antigen, and 40 to 50% in eight of the 10 control rats. In animals immunized against the antigen, there was a dramatic decrease, but not a complete suppression, in the capacity of epididymal spermatozoa to bind the zona pellucida as compared with the nonimmunized controls. Fertility was decreased two weeks after the end of the treatment, but partial restoration of fertility was observed 6 months later.

Linear and nonlinear mouse sperm motility patterns. A quantitative classification.

Abstract: A quantitative method is described for distinguishing two types of mouse sperm motility using a new parameter, the Linear Index. One hundred spermatozoa from C57BL/6-+/+ and 100 spermatozoa from C57BL/6-tw32/ + mice were used to evaluate this parameter. Spermatozoa were tracked by videomicrography, and the following calculated: net displacement velocity, Vn; curvilinear velocity of the sperm head, Vc; the "average" velocity, Va (a 5-point moving average of the track); the progressiveness ratio, (Vn/Vc); the curvilinear progressiveness ratio, (Va/Vc); and a linear index, (Vn/Va). Frequency histograms of linear index values were bimodal for both groups and each had a clear antimode at 0.5, separating two discrete subpopulations of spermatozoa. Within each group, "linear" (greater than 0.5) and "nonlinear" (less than 0.5) tracks differed in all characteristics; between groups, linear spermatozoa were similar and nonlinear spermatozoa differed only in the curvilinear velocity of the sperm head.

Evidence that estrogen regulation of testosterone secretion in adult rams is mediated by both indirect (gonadotropin dependent) and direct (gonadotropin independent) means.

Abstract: Involvement of endogenous estrogen in the regulation of gonadotropin and testosterone secretion was investigated in adult rams. Groups of four rams were either passively immunized against estradiol or treated with the antiestrogen tamoxifen for 2 weeks during the breeding season (October). Circulating testosterone levels in immunized rams increased eight-fold to supraphysiologic values as episodic elevations and baseline levels increased in magnitude; only moderate increases in LH peak frequency and magnitude occurred, and prolactin fell to undetectable levels. Tamoxifen treatment was not associated with changes in mean hormone levels, although there was a tendency toward reductions in the magnitude of episodic LH and testosterone secretion. When rams were challenged with exogenous GnRH and LH, a greater testicular endocrine response was observed in the immunized rams and the pituitary endocrine response was delayed in the tamoxifen-treated rams. Results indicate that in the ram 1) circulating levels of estradiol provide negative feedback signals of different intensities to the testis and the hypothalamic-pituitary axis and 2) tamoxifen exerts a mild estrogenic effect when administered at the dose of 25 mg/day.

Androgens in various fluid compartments of the rat testis and epididymis after hypophysectomy and gonadotropin supplementation

Abstract: Hypophysectomized male rats were administered LH or LH + FSH for 14 days and subjected to in vivo micropuncture collection of reproductive tract fluids to determine if FSH alters the compartmentalization of testosterone in the rat testis or of 5 alpha-dihydrotestosterone (DHT) in the epididymis. Testosterone and DHT concentrations were determined in cardiac blood serum, testicular venous serum, testicular interstitial fluid, and seminiferous tubule fluid, and in intraluminal fluid and tissue extracts from the caput and cauda epididymidis. Testosterone is the predominant androgen in the testis, and compared with control values, concentrations in venous sera, interstitial fluid, and tubule fluid were returned to values indistinguishable from controls by supplementation with 24 micrograms LH/day. 24 micrograms LH + 24 micrograms FSH/day did not augment the intratubular partition of testosterone. Epididymal DHT values were returned to control levels by LH alone, but additional supplementation with FSH significantly increased DHT from the caput epididymidis even further. It is speculated that FSH does not alter the compartmentalization of androgens in the rat testis, but may play a role in retaining androgens in the epididymis.

Differential release of polyamines by cultured rat Sertoli cells.

Abstract: Cellular and media concentrations of polyamines in Sertoli cell cultures were determined by fluorescent spectroscopy of dansylated compounds after separation by high-performance liquid chromatography. In spite of low cellular levels of putrescine, the Sertoli cells released relatively large amounts of putrescine and spermidine even after several media changes. The inclusion in the culture media of cortisol, insulin, and thyroxine significantly elevated cellular polyamine levels, altered the spermidine to spermine ratio, and enhanced putrescine release by 3- to 4-fold. No spermine, however, was detected in the media under any of the conditions studied. The polyamine concentrations in cultured Sertoli cells from 13-day-old rats and the pattern of polyamine release by these cells differed significantly from those in the Sertoli cells from 46-day-old rats. These data demonstrate the differential release of polyamines by cultured rat Sertoli cells. The profiles of polyamine secretion appear to be age-dependent, and the significance of this phenomenon is discussed.

Stagnation of blood in the microvasculature of the affected and contralateral testes of men with short-term torsion of the spermatic cord.

Abstract: Bilateral testicular biopsies from four men with a short duration (3 hours 10 minutes to 4 hours 30 minutes) of unilateral spermatic cord torsion and testicular biopsies from six men with irreversible brain death were used for the present investigation. Extensive light and electron microscopic studies and quantitative analyses of all biopsy materials were performed. The torsioned testes revealed variable degrees of damage to the seminiferous tubules, including germ cell disorganization and sloughing of immature germ cells. Ninety-five percent of the blood vessels from the biopsied tissue specimens were clogged with blood cells. The seminiferous tubules of the contralateral testis had normal germ cell arrangements and counts. However, 88% of the microvessels from the tissue biopsied from the contralateral testes were packed with blood cells, whereas only 10% of the blood vessels in the control biopsy specimen were clogged with blood cells. At the electron microscopic level, fewer tight junctions and enlarged pores were found between the endothelial cells of the affected vessels, and microvilli were completely absent from these endothelial cells. The clogging caused by blood cells in the affected vessels was so severe that no space was found between the membrane of the endothelial cell and the membrane of the blood cells. It has been suggested that local clogging by blood is responsible for the initiation of degenerative changes in the testes of men with unilateral torsion of the spermatic cord.

In vitro production of a TRH-homologous peptide and His-Pro diketopiperazine by human semen.

Abstract: Fresh human semen, diluted 1:1 v/v with 0.15 M NaCl- 0.05 M phosphate, pH 7.5, undergoes a 3-fold increase in total thyrotropin-releasing hormone (TRH) immunoreactivity on incubation at 4 C for 8 to 16 hours. To identify the mechanism for this increase, pooled human semen was incubated at 4, 37, and 60 C, and the change in composition of the immunoreactive TRH peptides was quantitated by high pressure liquid chromatography and radioimmunoassay of TRH. His-Pro diketopiperazine, a biologically active metabolite of TRH consisting of a cyclic dipeptide of histidine and proline, also was measured by specific RIA. The concentration of TRH (pGlu-His-Pro-NH2) dropped precipitously within the first hour after dilution and incubation at all temperatures studied. A hydrophobic TRH-homologous peptide with the amino acid composition (Glu,X,Y,Pro), where X and Y are neutral, nonaromatic amino acids, increased 8-fold during 16 hours of incubation at 4 C. This TRH-homologous peptide is not derived from TRH because it lacks the histidine is not derived from TRH because it lacks the histidine residue. A 3- to 23-fold increase in His-Pro diketopiperazine levels occurred after 4 hours at 37 C. This was not due primarily to enzymatic removal of the pyroglutamyl residue from TRH by pyroglutamate aminopeptidase, since about 1 hour after ejaculation the initial His-Pro diketopiperazine levels were 9.7 +/- 5.1 micrograms/ml, or approximately 1000-fold greater than the corresponding levels of seminal TRH. Because cycloheximide, which blocks ribosomal protein biosynthesis, did not inhibit in vitro production of the TRH-homologous peptide and the His-Pro cyclic dipeptide, these peptides, like TRH, most likely arise from post-translational cleavage and processing from pre-existing macromolecular precursor proteins.

Comparison of the penetration ability of human spermatozoa into bovine cervical mucus and zona-free hamster eggs.

Abstract: In vitro bovine cervical mucus (BCM) penetration tests, sperm penetration assays (SPA) using zona-free hamster eggs, and routine semen analyses were performed on a total of 136 freshly collected semen samples from men who were seen at an infertility clinic. The correlations between bovine cervical mucus penetration and other semen parameters were the percent motile spermatozoa (r = 0.48), progressive motility grade (r = 0.44), sperm count (X 10(6)/ml) (r = 0.47), the percent normal morphology (r = 0.32) and the percent eggs penetrated (r = 0.46) (P less than 0.0001 for each correlation coefficient). When known fertile (n = 32) and infertile (n = 18) groups were tested, positive mucus penetration was associated 75% correctly and positive egg penetration was associated 90% correctly to clinical status. The mucus test had no false-negative results and the SPA had no false-positive results in these groups. It appears, then, that the mucus test and sperm penetration assay, although contributing different elements of data to an infertility evaluation, are both useful adjuncts to a semen analysis.

Prolonged Suppression of Plasma LH Levels in Male Rats after a Single Injection of an LH-RH Agonist in Poly(DL-Lactide-Co-Glycolide) Microcapsules

Abstract: The authors have examined the effects of a subcutaneous injection of the LH-RH agonist D-Trp6-LH-RH formulated in biodegradable poly(DL-lactide-co-glycolide) microcapsules on plasma levels of D-Trp6LH-RH, LH, and PRL in adult, gonadectomized male rats. Immunoreactive D-Trp6-LH-RH was detectable in the plasma of these animals at 1, 2, 3, and 4 weeks after injection. LH concentrations were greatly reduced 1 week after administering the D-Trp6-LH-RH microcapsule, continued to decrease during the following week, and remained suppressed until the end of the study, 6 weeks after the injection. Plasma PRL levels appeared elevated 1 to 2 weeks after the injection and suppressed thereafter, but these effects were significant only in animals rendered hyperprolactinemic by transplantation of an isologous pituitary under the renal capsule. These results demonstrate that an LH-RH agonist formulated in biodegradable microcapsules and administered as a subcutaneous injection can exert marked biologic effects in rats for at least 6 weeks. These findings also suggest that prolonged exposure to an LH-RH agonist may first produce stimulation, followed by an inhibition of PRL release from both in situ and ectopic pituitaries.

Culture of ciliated and nonciliated cells from rat ductuli efferentes.

Abstract: The isolation and culture of ciliated and nonciliated cells from rat ductuli efferentes is described. Fragments of epithelium obtained after two collagenase digestions attached to plastic and to extracellular matrix and could be maintained in culture for at least 2 weeks. Ciliary beating in cells grown on epididymal extracellular matrix-coated plastic could be observed for up to 7 days in culture. Although cells maintained on this substrate retained organelles characteristic of cells in vivo, they assumed a flattened, squamous appearance. In contrast, cells growing on the surface of permeable supports impregnated with extracellular matrix were polarized and exhibited a cuboidal/columnar appearance. Androgen binding protein conjugated to colloidal gold was taken up by these cells via coated pits and was found sequentially in uncoated endosomes, multivesicular bodies and lysosomes.