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.

The role of Hv1 and CatSper channels in sperm activation

Abstract: Elevations of sperm intracellular pH and Ca2+ regulate sperm motility, chemotaxis, capacitation and the acrosome reaction, and play a vital role in the ability of the sperm cell to reach and fertilise the egg. In human spermatozoa, the flagellar voltage-gated proton channel Hv1 is the main H+ extrusion pathway that controls sperm intracellular pH, and the pH-dependent flagellar Ca2+ channel CatSper is the main pathway for Ca2+ entry as measured by the whole-cell patch clamp technique. Hv1 and CatSper channels are co-localized within the principal piece of the sperm flagellum. Hv1 is dedicated to proton extrusion from flagellum and is activated by membrane depolarisation, an alkaline extracellular environment, the endocannabinoid anandamide, and removal of extracellular zinc, a potent Hv1 blocker. The CatSper channel is strongly potentiated by intracellular alkalinisation. Since Hv1 and CatSper channels are located in the same subcellular domain, proton extrusion via Hv1 channels should induce intraflagellar alkalinisation and activate CatSper ion channels. Therefore the combined action of Hv1 and CatSper channels in human spermatozoa can induce elevation of both intracellular pH and Ca2+ required for sperm activation in the female reproductive tract. Here, we discuss how Hv1 and CatSper channels regulate human sperm physiology and the differences in control of sperm intracellular pH and Ca2+ between species.

Zinc is an essential trace element for spermatogenesis

Abstract: Zinc (Zn) plays important roles in various biological activities but there is little available information regarding its functions in spermatogenesis. In our current study, we further examined the role of Zn during spermatogenesis in the Japanese eel (Anguilla japonica). Human CG (hCG) was injected into the animals to induce spermatogenesis, after which the concentration of Zn in the testis increased in tandem with the progression of spermatogenesis. Staining of testicular cells with a Zn-specific fluorescent probe revealed that Zn accumulates in germ cells, particularly in the mitochondria of spermatogonia and spermatozoa. Using an in vitro testicular organ culture system for the Japanese eel, production of a Zn deficiency by chelation with N,N,N′,N′-tetrakis (2-pyridylemethyl)ethylenediamine (TPEN) caused apoptosis of the germ cells. However, this cell death was rescued by the addition of Zn to the cultures. Furthermore, an induced deficiency of Zn by TPEN chelation was found to inhibit the germ cell proliferation induced by 11-ketotestosterone (KT), a fish specific androgen, 17α,20β-dihydroxy-4-pregnen-3-one (DHP), the initiator of meiosis in fish, and estradiol-17β (E2), an inducer of spermatogonial stem-cell renewal. We also investigated the effects of Zn deficiency on sperm motility and observed that TPEN treatment of eel sperm suppressed the rate and duration of their motility but that co-treatment with Zn blocked the effects of TPEN. Our present results thus suggest that Zn is an essential trace element for the maintenance of germ cells, the progression spermatogenesis, and the regulation of sperm motility.

Effect of omega-3 polyunsaturated fatty acid supplementation on semen profile and enzymatic anti-oxidant capacity of seminal plasma in infertile men with idiopathic oligoasthenoteratospermia: a double-blind, placebo-controlled, randomised study

Abstract: Effective medical treatments of infertile men with idiopathic oligoasthenoteratospermia (OAT) have yet to be determined. This study considered two major aims: (i) to measure the changes in semen parameters, omega-3 fatty acids (FA) compositions and anti-oxidant activity; (ii) to determine if the administration of omega-3 FA affect semen quality in infertile men with OAT. Two hundred thirty-eight infertile men with idiopathic OAT were randomised to eicosapentaenoic (EPA) and docosahexaenoic acids (DHA), 1.84 g per day (EPAX 5500TG; Lysaker, Norway), or placebo for 32 weeks. The semen parameters were assessed according to WHO criteria, and the EPA and DHA concentrations were determined in red blood cells (RBCs), seminal plasma and sperm cells at baseline and 32-week treatment period. Of randomised subjects, 211 (88.7%) completed the full 32-week randomisation period. The anti-oxidant status of seminal plasma was also evaluated by measuring the superoxide dismutase (SOD) and catalase-like activity. In the total group of participants, all EPA and DHA levels in RBC, and seminal plasma, were statistically significantly correlated with those in spermatozoa (both P = 0.001). A significant improvement of sperm cell total count (from 38.7 ± 8.7 ' 10⁶ to 61.7 ± 11.2 ' 10⁶, P = 0.001) and sperm cell concentration (from 15.6 ± 4.1 ' 10⁶ per ml to 28.7 ± 4.4 ' 10⁶ per ml, P = 0.001) was observed in the omega-3 group. A significant positive correlation was found between the EPA and DHA in seminal plasma and the semen parameters. Seminal plasma EPA and DHA concentrations were positively correlated with seminal plasma SOD-like and catalase-like activity (both P = 0.001). In seminal plasma, both SOD-like and catalase-like activity were positively correlated with sperm count, sperm motility, and sperm morphology. Oligoasthenoteratospermic men with low levels of EPA and DHA may benefit from omega-3 FA supplementation. Further studies are warranted to shed more light on this important issue.

A computer-assisted assay for mouse sperm hyperactivation demonstrates that bicarbonate but not bovine serum albumin is required

Abstract: Mammalian sperm hyperactivation (HA) is a change in motility that accompanies capacitation (CAP) and is dependent on calcium (Ca) (Yanagimachi and Usui, Exp Cell Res 89:161, 1974). HA may be important for transport through the female tract and/or for fertilization. To develop an objective and quantitative assay for HA in individual mouse sperm, a computer-assisted motion-analysis system was used to describe sperm translational movements. To determine which movements were characteristic of HA, Ca-dependent motility was identified. This was done by incubating sperm with or without calcium (Ca+ or Ca- sperm, respectively), and determining the range of values for each motility parameter that was present only among Ca+ sperm. To do this, we compared frequency distributions of motility parameter values at the time of maximal CAP (90 min). CAP was monitored by measuring the level of in vitro fertilization and by evaluating the pattern of chlortetracycline binding to individual sperm heads [Ward and Storey, Dev Biol 104:287, 1984]. Two Ca-dependent motility subgroups were apparent: 1) a "slow-speed" subgroup with a curvilinear velocity (Vc) less than 169 microns/sec that had none of the characteristics expected of HA sperm; and 2) a subgroup with higher speeds (Vc greater than 169 microns/sec) and wider-amplitude head movements as measured by curvilinear progressiveness ratio (PRc less than 0.56). The latter subgroup was selected as HA, since the frequencies and time course were similar to those for CAP in the same population. Two media components known to be important for CAP, bicarbonate and bovine serum albumin (BSA) were then tested to determine whether they were necessary for HA. Incubation of sperm without bicarbonate prevented HA, but omitting BSA did not affect HA during the first 3 hrs. These data suggest that HA is not tightly coupled with CAP.