Sperm motility

About: Sperm motility is a research topic. Over the lifetime, 13874 publications have been published within this topic receiving 416587 citations. The topic is also known as: sperm movement & GO:0097722.

Rediscovering Sperm Ion Channels with the Patch-Clamp Technique

Abstract: Upon ejaculation, mammalian spermatozoa have to undergo a sequence of physiological transformations within the female reproductive tract that will allow them to reach and fertilize the egg. These include initiation of motility, hyperactivation of motility and perhaps chemotaxis toward the egg, and culminate in the acrosome reaction that permits sperm to penetrate the protective vestments of the egg. These physiological responses are triggered through the activation of sperm ion channels that cause elevations of sperm intracellular pH and Ca(2+) in response to certain cues within the female reproductive tract. Despite their key role in sperm physiology and their absolute requirement for the process of fertilization, sperm ion channels remain poorly understood due to the extreme difficulty in application of the patch-clamp technique to spermatozoa. This review covers the topic of sperm ion channels in the following order: first, we discuss how the intracellular Ca(2+) and pH signaling mediated by sperm ion channels controls sperm behavior during the process of fertilization. Then, we briefly cover the history of the methodology to study sperm ion channels, which culminated in the recent development of a reproducible whole-cell patch-clamp technique for mouse and human cells. We further discuss the main approaches used to patch-clamp mature mouse and human spermatozoa. Finally, we focus on the newly discovered sperm ion channels CatSper, KSper (Slo3) and HSper (H(v)1), identified by the sperm patch-clamp technique. We conclude that the patch-clamp technique has markedly improved and shifted our understanding of the sperm ion channels, in addition to revealing significant species-specific differences in these channels. This method is critical for identification of the molecular mechanisms that control sperm behavior within the female reproductive tract and make fertilization possible.

Association of 25-hydroxy-vitamin D levels with semen and hormonal parameters.

Abstract: Vitamin D levels have been linked to various health outcomes including reproductive disorders. The purpose of this study was to explore the association between serum vitamin D level (25-hydroxy-vitamin D, or 25OHD) and semen and hormonal parameters. This is a cross-sectional study that included 170 healthy men recruited for the study of spermatogenesis from the general population. Men completed general and reproductive health questionnaires, and donated blood and semen samples. The main measures were hormonal (total and free testosterone, sex hormone-binding globulin, estradiol, follicle-stimulating hormone and luteinizing hormone) and semen parameters, adjusted (n=147) for age, body mass index (BMI), season, alcohol intake and smoking, in relation to categories of vitamin D levels, determined a priori. The mean age of the study population was 29.0±8.5 years and mean BMI was 24.3±3.2 kg m(-2). The mean 25OHD was 34.1±15.06 ng ml(-1). BMI showed a negative association with 25OHD. Sperm concentration, sperm progressive motility, sperm morphology, and total progressively motile sperm count were lower in men with '25OHD≥50 ng ml(-1)' when compared to men with '20 ng ml(-1)≤25OHD<50 ng ml(-1)'. Total sperm count and total progressive motile sperm count were lower in men with '25OHD<20 ng ml(-1)' when compared to men with '20 ng ml(-1)≤25OHD<50 ng ml(-1)'. The adjusted means of various hormonal parameters did not show statistical difference in the different categories of 25OHD. In conclusion, serum vitamin D levels at high and low levels can be negatively associated with semen parameters.

Protein kinase C is present in human sperm: possible role in flagellar motility.

Abstract: We report the presence of protein kinase C (PKC) in ejaculated human sperm as revealed by enzymatic activity assay and indirect immunohistochemistry. PKC is localized in the equatorial segment and in the principal piece of the tail. Addition of phorbol 12-myristate 13-acetate resulted in increased flagellar motility that was blocked by known PKC inhibitors such as sphingosine, staurosporine, and 1-(5-isoquinoylinylsulfonyl)-2-methylpiperazine. A very good correlation (r = 0.9, P less than 0.001) was found between the percentage of PKC-stained sperm cells and motility. We propose that PKC is involved in the regulation of flagellar motility in human sperm.

Protective role of isoflavones against the toxic effect of cypermethrin on semen quality and testosterone levels of rabbits.

Abstract: Cypermethrin is considered as one of the endocrine disruptors. Isoflavones play an important role in various physiological processes in the body. It has both estrogenic and antioxidant effects. The objective of this study was to evaluate the protective role of isoflavones (2 mg/kg B.W) on semen quality and plasma testosterone levels of male New Zealand White rabbits given sublethal dose (24 mg/kg BW every other day for 12 weeks) of cypermethrin. Results showed that treatment with cypermethrin caused a significant decreases (P < 0.05) in ejaculate volume, sperm concentration, total sperm output, sperm motility (%), total motile sperm per ejaculate (TMS), packed sperm volume (PSV), semen initial fructose and plasma testosterone. In addition, live body weight (LBW), dry matter intake (DMI) and relative weights of testes and epididymis were decreased. On the other hand, treatment with cypermethrin increased (P < 0.05) the numbers of abnormal and dead sperms, and initial hydrogen ion concentration (pH). Results indicated that the presence of isoflavones together with cypermethrin was capable to minimize its harmful effects. Treatment with isoflavones alone had positive effects on some semen characteristics in spite of it is considered as estrogen-like compound. Since it causes significant increases in libido (by decreasing the reaction time), PSV, sperm motility and TMS, while abnormal and dead sperm were reduced compared to control animals. Meanwhile, isoflavones had no negative effect on ejaculate volume, total sperm output, sperm concentration, initial fructose concentration, pH and plasma testosterone levels. Results demonstrated the beneficial influences of isoflavones in reducing the negative effects of cypermethrin on reproductive characteristics of mature male rabbits. Interestingly, data showed that isoflavones alone caused an improvement in some semen quality and had no negative effects on male fertility, and did not have negative effects on male fertility.

Effect of Cryoprotective Additives and Cryopreservation Protocol on Sperm Membrane Lipid Peroxidation and Recovery of Motile Human Sperm

Abstract: Sperm membrane damage during cryopreservation reduces the recovery of motile sperm. The present study investigates changes in sperm motility and membrane lipid peroxidation (LPO) in response to two changes in the standard sperm cryopreservation/thawing methodology: 1) the addition of platelet-activating factor (PAF) and pentoxifylline (PTX) as cryoprotective additives, and 2) the alteration of sample thawing time. PAF (1 microM) and PTX (3 mM) were added to fresh sperm samples prior to cryopreservation. After 2 weeks the samples were thawed either quickly (5 minutes at 37 degrees C) or slowly (30 minutes at 4 degrees C) and evaluated for sperm motility and LPO. Thawing time influenced both post-thaw motility and LPO. Samples thawed quickly exhibited a 31% increase in motility recovery (35.2 +/- 4.3% in quick-thaw samples; 24.3 +/- 3.9% in slow-thaw samples) and a 23% lower LPO level (23.3 +/- 3.4% in quick-thaw samples; 30.09 +/- 4.4% in slow-thaw samples) compared to samples thawed slowly. Results also demonstrated that PAF (49 +/- 1.7%) or PTX (42.6 +/- 1.5%) enhance post-thaw motility in comparison to control (35.8 +/- 1.2%), whereas neither PAF nor PTX affect post-thaw LPO (19.1 +/- 2.2% in controls; 20.2 +/- 1.7% in PAF samples; 20.5 +/- 1.4% in PTX samples). These results support observations that there is a negative correlation between sperm motility and LPO in cryopreserved samples. The results also discount the hypothesis that LPO protection is a result of the cryoprotective action of PAF or PTX.