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Sperm plasma membrane

About: Sperm plasma membrane is a(n) research topic. Over the lifetime, 1016 publication(s) have been published within this topic receiving 49964 citation(s).


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Journal ArticleDOI
TL;DR: High levels of ROS are detrimental to the fertility potential both in natural and assisted conception states.
Abstract: Objective To summarize the role of reactive oxygen species (ROS) in the pathophysiology of human reproduction. Design Review of literature. Setting Fertility research center and obstetrics and gynecology department in a tertiary care facility. Result(s) ROS plays an essential role in the pathogenesis of many reproductive processes. In male-factor infertility, oxidative stress attacks the fluidity of the sperm plasma membrane and the integrity of DNA in the sperm nucleus. Reactive oxygen species induced DNA damage may accelerate the process of germ cell apoptosis, leading to the decline in sperm counts associated with male infertility. ROS mediated female fertility disorders share many pathogenic similarities with the ones on the male side. These similarities include a potential role in the pathophysiology of endometriosis and unexplained infertility. High follicular fluid ROS levels are associated with negative IVF outcomes, particularly in smokers. Moreover, oxidative stress may be responsible in hydrosalpingeal fluid mediated embryotoxicity as well as poor in vitro embryonic development. Conclusion(s) High levels of ROS are detrimental to the fertility potential both in natural and assisted conception states.

1,246 citations

Journal ArticleDOI
01 Dec 1996-Urology
TL;DR: From the current data it appears that no single adjuvant will be able to enhance the fertilizing capacity of sperm in infertile men, and a combination of the possible strategies that are not toxic at the dosage used would be a feasible approach.
Abstract: Human spermatozoa exhibit a capacity to generate ROS and initiate peroxidation of the unsaturated fatty acids in the sperm plasma membrane, which plays a key role in the etiology of male infertility. The short half-life and limited diffusion of these molecules is consistent with their physiologic role in key biological events such as acrosome reaction and hyperactivation. The intrinsic reactivity of these metabolites in peroxidative damage induced by ROS, particularly H2O2 and the superoxide anion, has been proposed as a major cause of defective sperm function in cases of male infertility. The number of antioxidants known to attack different stages of peroxidative damage is growing, and it will be of interest to compare alpha-tocopherol and ascorbic acid with these for their therapeutic potential in vitro and in vivo. Both spermatozoa and leukocytes generate ROS, although leukocytes produce much higher levels. The clinical significance of leukocyte presence in semen is controversial. Seminal plasma confers some protection against ROS damage because it contains enzymes that scavenge ROS, such as catalase and superoxide dismutase. A variety of defense mechanisms comprising a number of anti-oxidants can be employed to reduce or overcome oxidative stress caused by excessive ROS. Determination of male infertility etiology is important, as it will help us develop effective therapies to overcome excessive ROS generation. ROS can have both beneficial and detrimental effects on the spermatozoa and the balancing between the amounts of ROS produced and the amounts scavenged at any moment will determine whether a given sperm function will be promoted or jeopardized. Accurate assessment of ROS levels and, subsequently, OS is vital, as this will help clinicians both elucidate the fertility status and identify the subgroups of patients that respond or do not respond to these therapeutic strategies. The overt commercial claims of antioxidant benefits and supplements for fertility purposes must be cautiously looked into, until proper multicentered clinical trials are studied. From the current data it appears that no single adjuvant will be able to enhance the fertilizing capacity of sperm in infertile men, and a combination of the possible strategies that are not toxic at the dosage used would be a feasible approach.

868 citations

Journal ArticleDOI
TL;DR: The factors responsible for Y chromosome deletions in spermatozoa remain unresolved but may be one facet of a central reproductive problem: controlling the amount of oxidative stress experienced by germ cells during their differentiation and maturation in the male reproductive tract.
Abstract: Recent advances in understanding of male infertility have implicated two major causative factors, oxidative stress and Y chromosome deletions. A major cause of oxidative stress appears to be the high rate of reactive oxygen species generation associated with the retention of excess residual cytoplasm in the sperm midpiece. Other possible causes include the redox cycling of xenobiotics, and antioxidant depletion or apoptosis. Oxidative stress induces peroxidative damage in the sperm plasma membrane and DNA damage in both the mitochondrial and nuclear genomes. Nuclear DNA damage in the germ line of the father may be associated with pathology in the offspring, including childhood cancer and infertility. Gene deletions on the non-recombining region of the Y chromosome account for the infertility observed in about 15% of patients with azoospermia and 5-10% of subjects with severe oligozoospermia. The Y chromosome is particularly susceptible to gene deletions because of the inability of the haploid genome to deploy recombination repair in retrieving lost genetic information. Aberrant recombination, defective chromatin packaging, abortive apoptosis and oxidative stress may all be involved in the aetiology of DNA damage in the germ line. The factors responsible for Y chromosome deletions in spermatozoa remain unresolved but may be one facet of a central reproductive problem: controlling the amount of oxidative stress experienced by germ cells during their differentiation and maturation in the male reproductive tract.

671 citations

Journal ArticleDOI
TL;DR: The possible roles of cryoprotectants and additives are considered in the context of their putative interactions with the sperm plasma membrane and modern approaches to the laboratory assessment of spermatozoa after freeze-thawing are discussed.
Abstract: Basic concepts of cryopreservation and the causes of cryoinjury are reviewed. The possible roles of cryoprotectants and additives are considered in the context of their putative interactions with the sperm plasma membrane. Modern approaches to the laboratory assessment of spermatozoa after freeze-thawing are also briefly discussed.

601 citations

Journal ArticleDOI
TL;DR: The technique appeared to provide more reliable estimations of the percentage of functional cells than did motility estimations or assessments of acrosomal integrity, and demonstrated the sensitivity of the sperm plasma membrane to cold shock: virtually all cells rapidly became permeable to the stains after such stress.
Abstract: Carboxyfluorescein diacetate and propidium iodide were used as fluorescent stains to assess membrane integrity in sperm populations from ram and boar. The living spermatozoa were immobilized with low concentrations of formaldehyde so that individual stained cells could be observed in a suspension with the aid of a fluorescence microscope. Intracellular esterases liberated impermeant-free carboxyfluorescein from the permeant carboxyfluorescein diacetate and caused the product to accumulate and fluoresce green within the acrosome and the mitochondria as well as within the cytoplasm. Most of the spermatozoa (the intact ones) accumulated carboxyfluorescein in all compartments; however, a few cells (those with damaged plasma membranes) accumulated the stain only in the acrosome and/or the mitochondria, while others (all of whose membranes were damaged) remained entirely unstained. The impermeant propidium iodide did not stain any of the (intact) spermatozoa that accumulated carboxyfluorescein throughout their length, but stained all the others (the heads fluoresced red). The technique appeared to provide more reliable estimations of the percentage of functional cells than did motility estimations or assessments of acrosomal integrity (presence of normal apical ridge). The technique also demonstrated the sensitivity of the sperm plasma membrane to cold shock: virtually all cells rapidly became permeable to the stains after such stress. Assessments of boar sperm samples during preparative incubation for in-vitro fertilization indicated a considerable increase in the percentage of cells with damaged plasma membranes as incubation proceeded, in advance of the increase in the percentage of cells with discharged acrosomes.

590 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20221
202121
202029
201920
201827
201726