Showing papers on "Sperm motility published in 1985"

Human pregnancy by in vitro fertilization (IVF) using sperm aspirated from the epididymis

Abstract: Spermatozoa were collected by microaspiration from the corpus epididymidis of a 42-year-old man with secondary obstructive azoospermia and used for in vitro fertilization. At insemination 61% of the spermatozoa were motile, with a motility index of 157. One of five eggs was fertilized and this was subsequently transferred to the patient's wife at the two-cell stage. Ultrasound examination and changing hormone levels confirmed an on-going pregnancy, which is currently at 30 weeks of gestation. This technique will provide a useful alternative for the management of some infertile men with obstructive azoospermia.

Relationship between the movement characteristics of human spermatozoa and their ability to penetrate cervical mucus and zona-free hamster oocytes.

Abstract: In a group of normospermic donors exhibiting hamster oocyte penetration scores of 0-100%, multiple regression analysis indicated that only 20% of the variation in fertilizing potential could be explained by differences in the movement characteristics of the spermatozoa following incubation in vitro. When the movement characteristics of the spermatozoa in semen were considered this figure was reduced to 6.8% as a result of significant differences in the motility patterns exhibited by the seminal and post-incubation sperm populations. A much closer relationship was observed between the movement characteristics of human spermatozoa in semen and their ability to penetrate cervical mucus. When differences in motile sperm densities were taken into account, 76% of the variation in cervical mucus penetration could be accounted for by the existence of linear correlations with certain aspects of sperm movement (multiple R = 0.874). Of the various attributes of sperm motility measured (linear velocity of progression, frequency of rotation, amplitude of sperm head displacement, % rolling and % yawing), a failure to exhibit an adequate amplitude of lateral sperm head displacement was consistently found to be the most significant factor determining the success of sperm-cervical mucus interaction (R2 = 0.53).

Effects of pH, lactate, and viscoelastic drag on sperm motility: a species comparison.

Abstract: Little or no motility is observed when sperm from 5 mammalian species are incubated in vitro in their cauda epididymal fluid (CEF). We examined the effects of pH, lactate, and viscoelastic drag on sperm motility to determine whether these factors are responsible for this inhibition of motility. The pHs of CEF from bull, dog, rat, guinea pig, and hamster were 5.8, 6.2, 6.9, 6.9, and 7.2, respectively. The lactate concentration of epididymal semen collected from anesthetized animals ranged from 0.6 to 0.9, but increased almost 10-fold in samples from rats or dogs when measured 2 h postmortem. Increasing the pH of CEF to 7.0 resulted in the initiation of full motility for bull and dog sperm. Suspensions of sperm in buffer at various pHs (from 4.0 to 7.6) produced a sigmoidal motility curve for all species. All species, including bull and dog, showed almost full motility in buffer at a pH equal to the pH of their own CEF. Motility of bull and dog sperm showed greater inhibition with decreasing pH when suspended in CEF instead of buffer. The addition of 15 mM lactate, which has been shown to lower sperm intracellular pH, shifted the motility versus pH curves of all species toward higher pH. In bull and dog the addition of lactate produced a motility profile that was indistinguishable from that in their own CEF. The viscoelastic drag of the CEF of only two species, rat and hamster, was sufficiently high to inhibit sperm motility. We conclude that the low pH of the CEF from bulls and dogs plus the presence of lactate is sufficient to cause inhibition of motility.(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.

Evidence for a role for cellular alkalinization in the cyclic adenosine 3',5'-monophosphate-mediated initiation of motility in bovine caput spermatozoa.

Abstract: Bicarbonate ion, the local anesthetics procaine and dibucaine, and the ionophores monensin and nigericin have been shown to markedly increase the ability of agents that elevate cyclic adenosine monophosphate (cAMP) levels to initiate motility in bovine caput spermatozoa. A number of other weak bases, including theophylline. D-600 and dipyridamole, elevate cAMP levels maximally in caput sperm at low levels but induce motility only at high levels. These compounds thus appear to have a dual role in the initiation of motility, i.e., they elevate both cAMP levels and internal pH. Confirmation of this view was provided by the demonstration that bicarbonate ion and procaine permit initiation of motility by theophylline, D-600 and dipyridamole at markedly reduced levels. Also, forskolin (a neutral adenylate cyclase activator) elevates cyclic AMP levels in caput sperm but initiates motility only in the presence of bicarbonate or procaine, and the membrane-permeant cAMP analogue 8-bromo-cAMP is capable of inducing motility only in the presence of bicarbonate. Thus, motility in caput sperm is induced only under conditions that elevate both intracellular cAMP and pH, whereas caudal sperm motility is stimulated by an elevation of either cAMP or pH. These data suggest that the epididymal development of motility requires a maturational increase in internal pH. This suggestion was confirmed by direct measurement of the internal pH of caput and caudal sperm; the internal pH of the former was found to be 5.84 ± 0.1 and the latter 6.27 ± 0.05.

Are conventional sperm morphology and motility assessments of predictive value in subfertile men

Abstract: Sperm morphology and motility are believed to be important prognostic factors for fertility. Results of a group of 67 men investigated for primary infertility who had mean sperm concentrations greater than 5 million per ml and who later produced pregnancies, were compared with those of 67 matched controls who remained infertile. All female partners were potentially fertile. The groups were matched for other known prognostic factors for fertility, namely, wife's age, the duration of infertility, sperm concentration and varicocele size. There were no significant differences between the two groups overall in the (mean +/- SEM)% of sperm with normal morphology (58.3 +/- 2.1; 58.5 +/- 2.2), or motility (40.6 +/- 1.8; 37.0 +/- 2.0). However, among oligospermic men from the two groups, sperm motility was significantly higher (P less than 0.05) in the subsequently fertile group (43.1 +/- 2.6%) than in the persistently infertile group (33.3 +/- 3.7). These results indicate that sperm morphology as currently assessed may not be important in predicting fertility in subfertile men with a mean sperm concentration over 5 million/ml and the % sperm motility may only be a relevant predictor in oligospermic men.

Albumin is required to support the acrosome reaction but not capacitation in mouse spermatozoa in vitro.

Abstract: Albumin was required specifically for penetration of the zona pellucida (less than 10% of eggs fertilized in the absence of albumin), but was not required for capacitation. A similar rate of capacitation was observed in the presence of albumin at concentrations ranging from 30 to 1 mg/ml, while a slightly slower rate was observed in the presence of 0.25 and 0.1 mg albumin/ml. In the absence of albumin, capacitation occurred at a rate which lagged behind that of the albumin-incubated counterparts by about 30 min; once capacitated, the addition of albumin promoted rapid sperm penetration. In albumin-free media (+/- the macromolecule PVA), sperm motility was frequently reduced, with fewer cells exhibiting hyperactivated motility, but improvements were observed after introduction of albumin. Acrosome loss was significantly lower in the absence of albumin, but within 5 min of its addition at concentrations ranging from 30 to 0.1 mg/ml to capacitated sperm suspensions, acrosome loss was stimulated and reached levels similar to those seen in control samples. Therefore, albumin can trigger the acrosome reaction in capacitated spermatozoa. It appears to act by assisting in the removal of a surface-associated inhibitory component, the presence of which stabilizes the sperm membranes and inhibits the acrosome reaction.

Cauda epididymal sperm motility: a comparison among five species.

Abstract: Rat spermatozoa are immotile in the cauda epididymidis and are kept quiescent by a protein which increases viscoelasticity of cauda luminal fluid. How species-specific this phenomenon is, is unknown. In the present study, the motility of cauda epididymal spermatozoa of rats, hamsters, guinea pigs, rabbits and humans have been investigated. Sperm motility was observed in undiluted cauda sperm samples and in samples diluted with physiological diluents with or without Ca++, among others. Hamster sperm were studied in further detail to determine if the motility inhibiting factor in hamster cauda lumen fluid had characteristics similar to those previously described in the rat. Cauda fluid protein concentrations and apparent viscoelasticity were also determined and related to cauda sperm motility in all species. The results demonstrated that all species studied except rabbits have immotile sperm in their native cauda fluid and that additional Ca++ is not a factor in the initiation of motility. Cauda sperm immotility is not always related to fluid viscosity, however, so other as yet unknown mechanisms must be called upon in some species. The vigorous motility of rabbit spermatozoa in their native fluid implies that a fundamental difference exists in the relationship between epididymis and spermatozoa in rabbits from that observed in other species.

Microencapsulation of Bovine Spermatozoa

Abstract: Two experiments were conducted to examine the efficacy of microencapsulation of bovine spermatozoa for use in artificial insemination. In Exp. 1, sperm were encapsulated at three different concentrations (45, 90 and 180 X 10(6) sperm/ml) in either .75- or 1.5-mm (diameter) microcapsules and incubated in vitro for 24 h at 37 C. Unencapsulated samples of each concentration served as controls. Capsule contents were evaluated for percentage of sperm motility and intact acrosomes at 2, 12 and 24 h of incubation. Capsule fragility was evaluated after 24 h incubation. Viability of spermatozoa was not influenced by sperm concentration or capsule size, and compared with controls, cellular injury after encapsulation was not apparent. Fragility of capsules was unaffected by capsule size; however, as the sperm concentration increased, integrity of the capsules decreased (P less than .05). In Exp. 2, using frozen-thawed semen, the effect of egg yolk content, presence of glycerol and viability of spermatozoa on the success of microencapsulation was measured. The extender was 2.9% sodium citrate with glycerol (7% v/v) and either 0, 5, 10 or 15% egg yolk (v/v). Uniformity of capsules in size and shape was evaluated subjectively. Capsule integrity and uniformity were unaffected by glycerol, sperm viability or egg yolk level up to 10% v/v; however, encapsulation of spermatozoa in 15%-yolk buffer increased the heterogeneity in capsule size and shape. Viability of encapsulated spermatozoa was maximal for extenders containing 10 or 15% yolk v/v. Reduced viability for the 5% yolk extender was due to pre-encapsulation injury associated with freezing. Microencapsulation procedures are compatible with sperm viability and can be adapted to an acceptable extender system used in artificial insemination.

Spontaneous improvement in semen quality: regression towards the mean.

Abstract: Regression towards the mean was demonstrated in semen analyses from 216 donors for artificial insemination by selecting those with low sperm concentration (less than 40 X 10(6)/ml), low motility (less than 50%) or low motility index (less than 120) in the first test. For each characteristic, the result was significantly higher in the second test, the means for first and second tests being, for sperm concentration 28 and 56 million per ml (n = 14, P less than 0.01), for motility 42 and 55% (n = 14, P less than 0.01) and for the motility index 95 and 131 (n = 24, P less than 0.001). Regression towards the mean occurs whenever extremes of the range of a variable and selected for re-measurement. Many of the current treatments for oligospermia and asthenospermia have been promoted because semen quality improved during uncontrolled studies in which this phenomenon may have been operative. Using means of multiple samples before and following therapeutic intervention will not prevent regression towards the mean, only reduce its magnitude. Thus, placebos are essential in the evaluation of treatments for male infertility.

Fertility differences among male rabbits determined by heterospermic insemination of fluorochrome-labeled spermatozoa.

Abstract: Spermatozoa from different bucks were stained with different fluorochromes, mixed, and inseminated heterospermically. By altering the interval between insemination and luteinizing hormone injection, spermatozoa were allowed to reside in the female tract approximately 5, 10, or 15 h prior to ovulation. The number of functional spermatozoa, from each male of a pair used, that was transported to the site of fertilization was estimated by counting total number of differently stained spermatozoa that surrounded or fertilized each oocyte. Spermatozoa from split ejaculates within a male competed against each other equally, indicating that the staining procedure did not affect fertilization or functional spermatozoal transport rates. Three pairs of males with high initial semen quality (greater than 80% motility) differed in fertility primarily due to functional spermatozoal transport. Spermatozoal survival in the female tract and capacitation time played a role in differences in male fertility when heterospermic insemination occurred at variable times relative to ovulation. Differences in fertilization not accounted for by spermatozoal transport ratio raised the possibility that rate of egg penetration due to acrosomal enzyme differences may be important in determining male fertility. Therefore, total acrosin, hyaluronidase, and arylsulfatase activity in spermatozoa from specific bucks used in fertilization experiments were determined. Although there were trends favoring high fertility when enzyme content was higher, the difference was significant only for arylsulfatase in one buck.

Cross-sectional study of semen parameters in a large group of normal Chinese men.

Abstract: Testicular size, semen characteristics and serum reproductive hormone levels were studied in 1239 normal Chinese men. The mean testicular size of 17 ml in this group of subjects was similar to other reports in Orientals but was smaller than that reported in Caucasians. Semen volume, and the sperm count, motility and morphology were comparable to those described for Caucasian subjects. The cervical mucus penetration test (Kremer's test) and the zona-free hamster egg penetration test were also studied in some of the subjects. Age showed a positive correlation with the serum levels of FSH and LH, which were highly correlated with each other. Sperm concentration and the total sperm count were positively correlated with testicular volume, the length of abstinence, the % of sperm with an oval head, and the zona-free hamster egg penetration test, but were negatively correlated with serum FSH. Sperm motility was negatively correlated with the duration of abstinence but was positively correlated with the % normal sperm. The results constitute a normal data base from Chinese men for comparison with studies in male infertility and fertility regulation.

Involvement of zinc in the regulation of pHi, motility, and acrosome reactions in sea urchin sperm.

Abstract: When sperm of Strongylocentrotus purpuratus or Lytechinus pictus are diluted into seawater, motility is initiated; and when exposed to egg jelly, an acrosome reaction is induced. In the presence of a variety of structurally different metal chelators (0.1-1 mM EDTA, EGTA, phenanthroline, dipyridyl, cysteine, or dithiothreitol), motility initiation is delayed and the acrosome reaction is inhibited. Of the metals detected in the sperm of these two species, very low levels of Zn+2 (0.1 microM free Zn+2) uniquely prevent this chelator inhibition. L. pictus sperm concentrate 65Zn+2 from seawater, and EDTA removes 50% of the accumulated 65Zn+2 by 5 min. Since both sperm motility and acrosome reactions are in part regulated by intracellular pH (pHi), the effect of chelators on the sperm pHi was examined by using the fluorescent pH sensitive probe, 9-aminoacridine, EDTA depresses sperm pHi in both species, and 0.1 microM free Zn+2 reverses this pHi depression. When sperm are diluted into media that contain chelators, both NH4Cl and monensin (a Na+/H+ ionophore) increase the sperm pHi and reverse the chelator inhibition of sperm motility and acrosome reactions. The results of this study are consistent with the involvement of a trace metal (probably zinc) in the pHi regulation of sea urchin sperm and indicate a likely mechanism for the previously observed effects of chelators on sperm motility and acrosome reactions.

Acquisition of sperm motility and its maintenance during storage in the lizard, Lacerta vivipara.

Abstract: Lizard spermatozoa, which are non-motile in the testis, develop the ability to swim as they pass along the excurrent duct. The addition of caffeine, a phosphodiesterase inhibitor, induced forward motility in spermatozoa from the caput epididymidis and increased the velocity of spermatozoa from the distal part of the epididymis. Caffeine had no effect on the motility of testicular spermatozoa. This suggests that sperm motility in this species is cyclic AMP-dependent but this factor alone is not sufficient to induce testicular sperm motility. In samples from the distal region of the epididymis, sperm motility was maximal in April just after the breeding season and then decreased significantly during the following months. A parallel can be drawn between these data and the levels of testosterone in the plasma. In the lizard, as in mammals, the epididymis may play an important role in the maturation of spermatozoa.