Showing papers on "Sperm motility published in 1983"

Cyclic adenosine 3',5' monophosphate, calcium and protein phosphorylation in flagellar motility.

Abstract: cAMP and calcium are two important regulators of sperm flagellar motility. cAMP stimulates sperm motility by activating cAMP-dependent protein kinase and catalyzing the phosphorylation of sperm proteins. The stimulation of sperm motility by cAMP appears to be at two different levels. Evidence has been presented to suggest that cAMP-dependent phosphorylations may be required in order for motility to be initiated. In addition, cAMP-dependent phosphorylation appears to modulate specific parameters of motility resulting in higher beat frequency or greater wave amplitude. Calcium, on the other hand, when elevated intracellularly to 10(-6) M or higher, inhibits flagellar motility. The calcium-binding protein, calmodulin, appears to mediate a large number of effects of calcium on motility. Evidence suggests that calcium-calmodulin may be involved at the level of the membrane to pump calcium out of the flagellum. In addition, calcium-calmodulin may be involved in the control of axonemal function by regulating dynein ATPase and myosin light chain kinase activities. The identification of cAMP-dependent protein kinase, calmodulin and myosin light chain kinase in the sperm head suggests that cAMP and calcium-dependent phosphorylations are also involved in the control of the fertilization process, i.e., the acrosome reaction, in a manner similar to that known for the control of stimulus/secretion coupling. Finally, the effects of cAMP on flagellar motility are mediated by protein phosphorylation while the effects of calcium on motility are also in part, mediated by effects on protein phosphorylation.

Significance of the need for sperm capacitation before fertilization in eutherian mammals.

Abstract: In order to fertilize, the spermatozoa of eutherian mammals must undergo capacitation in the female tract. The subcellular changes involved in capacitation finally seem to permit the influx of Ca2+ required for onset of the acrosome reaction, and they result also in a hyperactivated form of motility. However, why capacitation has appeared as an essential prerequisite for eutherian fertilization is unknown. Both these facets of capacitation may reflect new cellular control mechanisms for regulating the sperm's activities, necessitated by evolutionary change in the oocyte. The first may reflect a loss of the oocyte's stimulation of the acrosome reaction, and the second a concomitant appearance of unusually formidable egg vestments the spermatozoon must penetrate. Coordination of the rate of capacitation appropriate to fertilization in vivo may depend not only on the minimal time ordained for the species, but also on a heterogeneity among subpopulations of spermatozoa within any one sample and the timing of sperm transport to the oviduct.

Effects of potassium and osmolality on spermatozoan motility of salmonid fishes

Abstract: In salmonid fishes, rainbow trout and masu salmon, and the plecoglossid fish, ayu, seminal plasma had an osmolality around 300 mosmol kg-1 isotonic to the blood plasma, and contained a higher concentration of potassium than the blood plasma. Spermatozoa of salmonid fishes were motile when semen was diluted 1:100 with solutions of sodium chloride or mannitol, over the osmotic range of 0–300 mosmol kg-1. They were immotile in sodium chloride solution containing several mM potassium. This indicates that osmolality is not an essential determinant of sperm motility in the Salmonidae, and that sperm motility in these species is suppressed by the seminal potassium in the sperm duct, and initiated by a decrease in potassium concentration surrounding spawned spermatozoa when they are released into fresh water.

An evaluation of human sperm as indicators of chemically induced alterations of spermatogenic function. A report of the U.S. Environmental Protection Agency Gene-Tox Program.

Abstract: To evaluate the utility of sperm tests as indicators of chemical effects on human spermatogenesis, the literature on 4 sperm tests used to assess chemically induced testicular dysfunction was reviewed. The tests surveyed included sperm count, motility, morphology (seminal cytology), and double Y-body (a fluorescence-based test thought to detect Y-chromosomal nondisjunction). There were 132 papers that provided sufficient data for evaluation. These reports encompassed 89 different chemical exposures: 53 were to single agents; 14 to complex mixtures; and 22 to combinations of 2 or more identified agents. Approximately 85% of the exposures were to experimental or therapeutic drugs, 10% were to occupational or environmental agents, and 5% were to drugs for personal use. The most common sperm parameter studied was sperm count (for 87 of the 89 exposures reviewed). Sperm motility was evaluated for 59 exposures, morphology for 44, and double Y-bodies for only 4. The 89 exposures reviewed were grouped into 4 classes: those which adversely effected spermatogenesis, as measured by one or more of the sperm tests (52); those suggestive of improving semen quality (11); those showing inconclusive evidence of adverse effects from exposure (14); and those showing no significant changes (12). Since the reviewed reports had a large variety of study designs, and since every attempt was made to include all reports with interpretable data, these classifications were based on reviewing committee decisions rather than on uniform statistical criteria. This review gives strong evidence that human sperm tests can be used to identify chemicals that affect sperm production, but because of our limited understanding of underlying mechanisms, the extent to which they can detect mutagens, carcinogens or agents that affect fertility remains uncertain. For the very few agents studied with both human and mouse sperm tests, similar test-responses were seen; thus sperm tests in mice and other laboratory mammals may have a potential role in hazard identification. An overall comparison of the 4 human sperm tests suggests that no one test is biologically more responsive than another; all of them may thus be needed when testing for chemically induced changes from agents of unknown activity. This review also gives evidence that sperm tests can be used to assess the extent and the potential reversibility of induced spermatogenic damage. The reviewing committee recommends further studies to determine (a) the dose-response characteristics of the human sperm tests, (b) details of the reversibility of induced changes with time after exposure, (c) the relative responses in the 4 sperm tests in exposed individuals, (d) the mechanism of action, (e) the biological and genetic implications of chemically induced effects, and (f) the comparison of responses among different species for risk assessment. The reviewing committee outlines specific considerations for planning new sperm studies on chemically exposed men.

Potassium-dependent increases in cytosolic pH stimulate metabolism and motility of mammalian sperm

Abstract: Sperm cytosolic pH, determined by the spectral properties of intracellular carboxyfluorescein, is decreased rapidly by the diffusion and subsequent dissociation of the uncharged weak acids pyruvic, lactic, or hydroxybutyric and is increased by diffusion and subsequent intracellular protonation of the weak base NH3. Metabolic and kinetic activity increases dramatically when intracellular pH is elevated above 6.8-6.9 by addition of 50 mM NH4Cl to sperm suspended in a 120 mM NaCl medium. Respiratory stimulation is not observed upon comparable additions of 50 mM Li+ or K+ or when the pH of the medium is increased from 6.5 to 8.2. However, increases of the external pH to 7.8-8.2 in medium employing 120 mM KCl result in increased metabolic and kinetic activity, comparable to the maximal stimulation induced by the phosphodiesterase inhibitor caffeine. An increase in cytosolic pH from 6.3-6.6 to 6.8 occurs concomitant with the respiratory stimulation induced by KCl in alkaline media. No change in cytosolic pH follows addition of caffeine. Cyclic AMP-dependent protein kinase activity ratios, determined in cellular extracts, are increased by caffeine treatment but are not elevated by 120 mM KCl, by alkaline pH, or by their combination. These observations indicate that cytosolic pH plays a role in the regulation of motility and metabolism of mammalian sperm that is not mediated by cyclic AMP but that may be under control of a plasma membrane voltage-dependent proton channel. However, H+ fluxes across vesicles prepared from sperm membranes are unaffected by variation in the magnitude of the transvesicular K+ concentration gradient.

Movement characteristics and acrosomal status of rabbit spermatozoa recovered at the site and time of fertilization.

Abstract: Rabbit spermatozoa were recovered from the oviductal ampullae 11 h postcoitus by an oil microflush technique. Their movement was evaluated in the ampullar fluid, or in ampullar fluid diluted with in vitro fertilization medium, in slide preparations which were approximately 25 micron or 100 micron deep. The movement of these sperm was compared with the movement of ejaculated sperm in diluted semen. Movement parameters measured from videotapes recorded by a high-speed camera were coded according to treatment and entered into a microcomputer for statistical analysis. A total of 157 spermatozoa were recovered from the oviducts of 16 does: 152 were motile and 126 were free-swimming. Nearly all of the free-swimming sperm swam in trajectories whose average paths were circular. The flagellar beat pattern of the circular swimmers was asymmetric and nearly planar, and the sperm did not roll. Spermatozoa observed in 25-micron slide preparations produced smaller flagellar bends than sperm swimming in 100-micron preparations and tended to swim in larger circles which were oriented in the plane of the slide. Spermatozoa observed within the cumulus matrix moved in a slow, erratic, sinuous manner, but resumed rapid circling upon leaving the matrix. It was concluded that the ampullar sperm were hyperactivated, retaining this physiological condition as they entered the cumulus. The movement qualitatively resembled that of hyperactivated guinea pig and hamster spermatozoa because these species effectively swim in circles. In contrast, 80% of the ejaculated spermatozoa swam in linear trajectories, resulting from relatively symmetrical, flagellar beat patterns. The percentage of rolling spermatozoa and the rolling frequencies were less in the 25-micron than the 100-micron slide preparations. Thus, the movement parameters of both ampullar and ejaculated spermatozoa were affected by the geometry of their observation chambers. This influence should be taken into account when observing sperm motility in vitro. It could also be important in vivo, where changes in sperm movement in response to epithelial surfaces might provide an advantage for reaching the cumulus mass. Ninety-eight percent of the motile ampullar sperm were observed to have acrosomes, including all spermatozoa found within the cumulus matrix.

Male and female infertility problems in the immotile-cilia syndrome.

Abstract: The immotile-cilia syndrome is a heterogeneous disease. The dynein arms were missing totally or almost totally, and both spermatozoa and cilia were immotile in most cases examined by us. In other cases, the ciliary axoneme displayed other defects and the spermatozoa had motility although restricted; there was no progressive motility. Fourteen men with this syndrome were all sterile. Fifteen women had the syndrome and twelve tried to become pregnant. This had been successful (one, one, and two children) in three cases only. Thus, it appears that female fertility is also impaired in this syndrome, although not completely. No case of ectopic pregnancy has been reported.

Rat sperm are mechanically immobilized in the caudal epididymis by "immobilin," a high molecular weight glycoprotein.

Abstract: In many mammals, sperm are immotile while stored in the caudal epididymis and do not become motile until ejaculation. We report here our investigation of the mechanism that initiates motility in mature rat epididymal sperm. We found that an external "activator" is not required to initiate rat sperm motility since immotile sperm started to swim immediately when exposed to solutions that contributed only osmotic support. Instead, we found that epididymal rat sperm are kept fully immobilized by a high molecular weight glycoprotein, "immobilin," that we have isolated from rat cauda epididymal (CE) fluid. Our results strongly support the hypothesis that immobilin inhibits sperm motility mechanically simply by creating a highly viscoelastic environment: 1) rat CE fluid inhibited the motility of such disparate cells as rat sperm, E. coli. and rabbit sperm (which are fully motile in rabbit CE fluid), 2) the degree to which a variety of enzymatic treatments or slight dilution of the CE fluid initiated sperm motility depended only on the degree to which the treatment reduced the viscoelastic drag of the fluid, and 3) centrifugation of CE fluid simultaneously copurified the component of the fluid that immobilizes the sperm, the component that renders the fluid viscoelastic, and the glycoprotein immobilin.

Epididymal Functions and their Hormonal Regulation

Abstract: The epididymis is a complex organ which maintains a specific intraluminal environment thought to be important for effecting sperm maturation in proximal regions and sperm storage in distal regions of the duct The composition of the internal milieu is achieved both by transport between blood and lumen (and vice versa) and by synthesis and secretion into the lumen Several low-molecular weight organic molecules achieve high concentration in the epididymal lumen, but their functions in the events of sperm maturation and storage still remain unclear Metabolic processes occurring within epididymal tissue and the absorptive and secretory activity of the epididymal epithelium are regulated by androgens The synthesis of some, but not all, secretory proteins is also androgen-dependent In addition to androgens, other hormones and local testicular factors may influence epididymal function There is now increasing evidence that epididymal-specific and androgen-dependent secretory proteins play a fundamental role in modifying the surface characteristics of sperm in preparation for the events of fertilization

Sperm morphology assessment as an indicator of human fertilizing capacity.

Abstract: Semen samples from 95 men were examined by routine semen analysis and specific histologic staining for sperm morphology. The men were classified into fertile and infertile groups on the basis of clinical evaluation and in vitro testing, using the zona-free hamster egg penetration assay. Thirty men were designated as fertile, as they had fathered children and their sperm showed penetration of greater than 20% of the zona-free hamster eggs with the in vitro fertilization test. Subjects classified as infertile were men from infertile couples whose wives showed no evidence of infertility and whose in vitro fertilization ability was 10% or less. The semen analysis parameters of the fertile and infertile groups were significantly different. Fertile men had mean values of 108 X 10(6) sperm/ml, 61% motile, 64% normal forms (sperm with oval morphology), and 69% penetration in vitro. The mean values for infertile men were significantly lower: 42 X 10(6) sperm/ml, 45% motile, 32% normal forms, and 3.2% penetration in vitro. The importance of the morphology parameter was revealed by comparison of the percentage of penetration with count, motility, and morphology. Penetration correlated best with morphology (r = 0.730) as compared with motility (r = 0.451) and count (r = 0.605). The distribution of abnormalities in the infertile group revealed 81.6% with abnormal morphology (less than 50%), 53.8% with abnormal motility (less than 50%), and 38.5% with abnormal count (less than 20 million/ml). As a single parameter, decreased number of normal forms appears to be a good indicator for clinical infertility if in vitro fertilization testing is not available.

Effects of coelomic and seminal fluids and various saline diluents on the fertilizing ability of spermatozoa in the rainbow trout, Salmo gairdneri.

Abstract: When trout (Salmo gairdneri) spermatozoa were diluted in coelomic fluid or saline diluents at high dilution rates of 10(-3) and 10(-2) for increasing periods of time before insemination, there was a rapid decline and loss of fertilizing ability. At a lower dilution rate of 10(-1), there was partial or no loss of fertility. Dilution in a KCl-enriched saline diluent to inhibit sperm motility produced a slight decrease in fertility at a 10(-3) dilution rate, indicating that the spermatozoa, although sensitive to dilution, were less so when they were kept immotile. A partial loss of fertility was observed after the spermatozoa or eggs had been washed with saline diluents. The loss of fertility was total when both gametes were washed. Removing the seminal fluid by centrifugation led to a significant decrease in the fertilizing ability of the spermatozoa when insemination was carried out in saline diluent but not in coelomic fluid. Adding BSA at high doses (10 mg BSA/ml) into the diluent led to longer survival of the diluted spermatozoa. We conclude that (1) sperm dilution rate is a major factor in the maintenance of fertilizing ability of diluted salmonid spermatozoa, (2) as reported in the literature, coelomic fluid is superior to mineral diluents only when the gametes have been washed, and (3) some substances (possibly proteins) present in seminal and coelomic fluids play a role in gamete protection. These findings may explain the discrepancies in the literature concerning the duration of motility and fertilizing ability of salmonid spermatozoa.

Influence of caffeine on movement characteristics, fertilizing capacity and ability to penetrate cervical mucus of human spermatozoa

Abstract: Summary. When added to frozen\p=n-\thawedhuman semen, the 3 doses of caffeine tested (2, 5 and 10 mM) induced a significant increase in the percentage of motile spermatozoa but did not influence the quality of movement. Considerable variability was noted between samples in their responsiveness to caffeine which, at the 5 and 10 mM doses, was significantly correlated with the degree of motility lost during cryostorage. Caffeine treatment of frozen\p=n-\thawedhuman spermatozoa also increased the number of spermatozoa penetrating cervical mucus in unit time, by increasing the frequency rather than the success of collisions between spermatozoa and the cervical mucus interface. When caffeine-stimulated spermatozoa were washed free of seminal plasma containing this compound they were no longer at an advantage with respect to their motility or fertilizing ability. When 2 mM-caffeine was added to washed suspensions of capacitated spermatozoa it failed to stimulate motility but did significantly enhance the fertilizing ability of the spermatozoa, indicating a possible clinical role for this compound in in-vitro fertilization therapy.

Effects of Occupational Exposure to Lead on Sperm and Semen

Abstract: Semen qualities were studied in samples from workers exposed to lead in a factory for storage batteries. The study included two groups with different degrees of exposure. The mean lead-blood concentration (Pb-B) values for the men in the two groups during the six months preceding the study were 45 µg/100 ml and 22 µg/100 ml, respectively. Each man delivered at least one semen sample during a test period and most of the men participated in both test periods, which took place within a six-month interval. The size of each of the four groups, was 16 or more men. The semen qualities assessed included sperm count, sperm motility (qualitative and quantitative), sperm morphology, sperm chromatin stability when exposed to sodium dodecyl sulphate, and release of LDH-X into the seminal plasma. The secretory function of the prostate was assessed by analyses of such markers as acid phosphatase, zinc, and magnesium. Fructose was used as the marker for the secretory function of the seminal vesicles. All semen samples had values within the expected limits for that population. A subtle but significant difference was found between the two groups for sperm chromatin stability, indicating that the exposure to lead had decreased the stability of the spermatozoa. Moreover, a decreased secretory function of the accessory genital glands was noted more frequently among the men with the higher degree of exposure than among those in the other group. For all other semen variables, there were no differences between the groups.

Potassium movement during sodium-induced motility initiation in the rat caudal epididymal spermatozoa.

Abstract: The sodium-induced sperm motility initiation of the rat cauda epididymal sperm has been studied in different potassium concentrations High K+ inhibited motility initiation At a K+ concentration of 50 mM (concentration found in the rat cauda epididymidis), sperm motility was inhibited by 80% K+ movement across the sperm membrane has been followed by using 86Rb+ as a marker for K+ When the 86Rb+ preloaded sperm were suspended in a sodium-free medium, there was a little efflux of 86Rb+ However, if they were suspended in a sodium-containing medium, the efflux rate was greatly increased This increase in 86Rb+ efflux rate was associated with an initiation of sperm motility Both 86Rb+ efflux and motility initiation were triggered by a K+ ionophore 18-crown-6 (2 X 10(-3)M) However, the ionophore-induced 86Rb+ efflux and motility initiation only occurred in the presence of extracellular Na+ Tetraethylammonium (TEA) chloride, which blocks K+ channels, inhibited motility initiation in a dose-dependent manner Changes in the membrane potential of sperm have been followed using the fluorescent dye diO-C6-(3) whose fluorescence in sperm suspension changes markedly with changes in sperm membrane potential During motility initiation, there was a fall in fluorescence of the dye due to increased partition into sperm cells This observation may indicate a hyperpolarization of the sperm membrane during motility initiation It was concluded that sperm motility initiation is associated with a complex ionic event Na+ enters sperm cells in exchange with H+ and K+ This change in the permeability of the sperm membrane to ions is reflected by a change in the sperm membrane potential

Movement characteristics of bovine epididymal spermatozoa: effects of forward motility protein and epididymal maturation.

Abstract: Movement characteristics of untreated bovine caudal epididymal spermatozoa were compared by high-speed cinemicrography with those of theophylline-activated caput epididymal spermatozoa with and without added forward motility protein (FMP). Comparison of individual movement characteristics clearly established the importance of FMP in converting the nonprogressive motility of theophylline-activated caput sperm into the progressive swimming of mature caudal sperm. Although the total or curvilinear distance traveled in 1 sec by theophylline-activated caput sperm was not changed by the addition of FMP, the linear progression was doubled and the percentage of progressively motile sperm was tripled by this protein. Untreated caudal sperm were 80% motile and theophylline-activated caput sperm were nearly 50% motile; the percentage of motile sperm that were progressive was the same for theophylline-activated caput sperm with FMP and for untreated caudal sperm. Caput sperm without FMP roll infrequently, if at all, but caput sperm with FMP and caudal sperm roll at 4.7 Hz. The beat frequency increases significantly with the addition of FMP and is even higher for caudal sperm. The hydrodynamic power output rises concomitantly with the beat frequency. Perhaps the most striking difference between caput sperm without FMP and those with it is in the swimming paths they follow. Caput sperm without FMP exhibit frequent reversals in direction, or yawing of the sperm heads as they loop back and cross over their tails in an apparently very flexible bending. Their average swimming paths are circles. Caput sperm with FMP and caudal sperm do not show this behavior, but swim in average paths which are linear. The minimum radius of curvature of the tail of caput sperm without FMP is much smaller than that for the other two cell types. These studies clarify the role of FMP in epididymal development of sperm motility.

Is conventional sperm analysis of any use

Abstract: The computerised records of 867 couples were used to investigate the prognostic significance of semen volume, motility, density and morphology The couple-months method of statistical analysis was used, with allowance being made for the duration of involuntary infertility (trying time) Both motility and density were shown to give independent prognostic information, and a table of estimated probabilities is presented which may be helpful when advising the infertile couple on their chances of future conception If the product of the motility times the density exceeded 05 million motile sperm per ml, then one semen analysis was sufficient from the point of view of giving a prognosis

Combined treatment with an LHRH agonist and testosterone in man: reversible oligozoospermia without impotence.

Abstract: We have previously shown that LHRH agonist [D-Trp Pro -Net]LHRH (LHRHA) results in reversible oligozoospermia when given to normal subjects for up to 10 weeks. A fall in plasma testosterone was accompanied by loss of libido and potency. The authors now report on 6 subjects who were evaluated by semen analysis and hormone profile at 2-week intervals during 10-week basal 20-week treatment and posttreatment periods lasting at least 10 weeks. Treatment consisted of LHRHA (50 mcg subcutaneously daily) and testosterone enanthate (100 mg intramuscularly every 2 weeks). Sperm density (mean basal 76.7 +or- 8.7x10 /ml) fell consistently in each subject to a mean nadir of 12.3 +or- 4.5x10 /ml (P /ml achieved when LHRHA was given alone. In each individual subject sperm density returned to his basal level after cessation of treatment. No consistent changes were seen in sperm motility or morphology or in semen volume. Libido and potency were maintained in all subjects. An additional 3 subjects received testosterone enanthate alone in identical dosage for 20 weeks. No change in sperm density was observed. In contrast to treatment with LHRHA alone combination treatment produces reversible oligozoospermia without attendant change in potency. (authors)

Electroejaculation and semen analysis and freezing in the giant panda (Ailuropoda melanoleuca)

Abstract: Summary. Semen was collected by a standardized electroejaculation procedure from a giant panda on 4 occasions. Ejaculate volume, sperm count and % sperm motility were 2\m=.\3\p=n-\3\m=.\6ml, 62\p=n-\562\m=x\ 106 spermatozoa/ml and 45\p=n-\85%respectively. The results, although limited to a single male, suggested a seasonal influence on ejaculate and gonadal parameters with improved ejaculate volume, sperm motility and increased testicular size in the season proximate to the female's oestrous period. Frozen\p=n-\thawed spermatozoa were motile with no apparent abnormalities induced by the freezing procedure.

Effect of gossypol on the motility and metabolism of human spermatozoa

Abstract: Gossypol, a polycyclic compound isolated from cotton seeds, had a dose-dependent inhibitory effect on human sperm motility. The drug also inhibited powerfully fructolysis and glycolysis by human spermatozoa. Both lactate and CO2 formation from the 14C-labelled sugars was inhibited, and the prevention of CO2 formation from [1-14C]pyruvate and [2-14C]pyruvate by gossypol indicated a direct effect on the tricarboxylic acid cycle. Repeated washing of the sperm cells after gossypol pretreatment failed to abolish the inhibitory effect on CO2 production. The profound disturbances of the sperm energy metabolism induced by gossypol were also reflected by a striking fall of the sperm ATP content. Gossypol had little effect on glucose utilization by minces of human vaginal mucosa, indicating the specificity of gossypol.