Sperm Acrosin Activity Research Articles

ACE Gene Insertion/Deletion Polymorphism Seminal Associations in Infertile Men

We assessed seminal associations of the ACE gene insertion/deletion polymorphism in infertile men. A total of 405 men were investigated, divided into healthy fertile men, and those with asthenozoospermia, asthenoteratozoospermia and oligoasthenoteratozoospermia, respectively. They underwent semen analysis, and assessment of sperm acrosin activity, hypo-osmotic swelling, seminal 8-iso-prostaglandin-F(2α), total antioxidant capacity, α-glucosidase and ACE gene polymorphisms. The ACE insertion/insertion genotype was noted in 182 men, including 76.5% of healthy fertile men, and 47.4%, 39.8% and 17.6% of those with asthenozoospermia, asthenoteratozoospermia and oligoasthenoteratozoospermia, respectively. The ACE insertion/deletion genotype was noted in 133 men, including 13.7% of healthy fertile men, and 42.3%, 27.5% and 47.2% of those with asthenozoospermia, asthenoteratozoospermia and oligoasthenoteratozoospermia, respectively. The ACE deletion/deletion genotype was identified in 90 men, including 9.8% of healthy fertile men, 10.3%, 32.70% and 35.2% of those with asthenozoospermia, asthenoteratozoospermia and oligoasthenoteratozoospermia, respectively. Men with the ACE deletion/deletion and insertion/deletion genotypes showed a significant decrease in sperm count, motility, linear velocity and normal forms, acrosin activity index, hypo-osmotic swelling test and seminal α-glucosidase, and significantly increased seminal 8-iso-prostaglandin-F(2α) than those with the ACE insertion/insertion genotype. ACE gene deletion polymorphism is associated with abnormal seminal variables, such that carriers of the ACE deletion/deletion genotype have higher seminal oxidative stress.

The relationship between the sperm quality and fertilization outcome after short-time insemination

Objective To evaluate the predictive value of the sperm quality to fertilization outcomes after short-time insemination. Methods A total of 558 cycles of short-time insemination in the Reproductive Medical Center of Henan Provincial People′s Hospital during January 2009 to June 2010 excluding patients aged >38 years and M II oocyte number <3 were analyzed retrospectively.According to whether undergo rescue intracytoplasmic sperm injection(Re-ICSI), all cycles were divided into in vitro fertilization (IVF) group (472 cycles) and rescue intracytoplasmic sperm injection (Re-ICSI) group(86 cycles).Both IVF group and Re-ICSI group were subdivided into primary infertility and secondary infertility according to previous history of pregnancy.269 primary infertility cycles and 203 secondary infertility cycles were characterized in IVF group; and 64 primary infertility cycles and 22 secondary infertility cycles were characterized in Re-ICSI group.χ2 test was applied for comparison of embryo plant rate, clinical pregnancy rate, early miscarriage rate between IVF and Re-ICSI groups , while Fisher test was used for comparison of live birth rate.and Mann-Whitney U test was utilized for comparison of duration of infertility, forward moving sperm counts, abnormal sperm rate, sperm acrosin activity between IVF and Re-ICSI groups. Results The embryo plant rate, clinical pregnancy rate, early miscarriage rate, live birth rate of IVF group were: 29.4%, 44.9%, 13.4%, 37.0% respectively；the above indicators in Re-ICSI group were: 25.7%, 34.6%, 10.7%, 29.6% respectively, the differences of the indicators between the two groups had no statistical significance（χ2=0.869, 2.963, 0.010, P=0.351, 0.085, 0.922, 0.098）.Median of duration of infertility, forward moving sperm counts, abnormal sperm rate, sperm acrosin activity of primary infertility cycles in IVF group were:4.00(3.00-6.00) years, 58.37(33.64-102.27)×106, 81.09%(79.41%-88.69%), 76.30(48.50-92.46) μIU/106 sperm respectively; in Re-ICSI group were: 5.00(3.25-8.00) years, 36.33(20.59-64.43)×106, 85.5%(81.28%-89.02%), 47.14(31.61-90.24) μIU/106 sperm respectively, the differences of them between the two groups had statistical significance（Z=-2.617, -3.505, -3.553, -3.530, P=0.009, 0.000, 0.000, 0.000）.Median of duration of infertility, forward moving sperm counts, abnormal sperm rate, sperm acrosin activity of secondary infertility cycles in IVF group were: 5.00(3.00-7.00) years, 63.00(34.20-107.73)×106, 81.29%(79.90-86.09）%, 78.34 (53.87-98.00) μIU/106 sperm respectively, in Re-ICSI group were: 5.00(3.75-7.00) years, 28.80(18.57-48.56)×106, 88.79%(84.04-95.64)%, 54.70(39.73-76.77) μIU/106 sperm respectively, the differences of them between the two groups showed statistical significance except duration of infertility (Z=-0.338, -3.505, -3.553, -3.530, P=0.735, 0.000, 0.000, 0.006）. Conclusion The duration of infertility, forward moving sperm counts, abnormal sperm rate, sperm acrosin activity have predictive value of fertilization outcomes after short-time insemination.(Chin J Lab Med, 2012，35：150-155) Key words: Fertilization in vitro; Treatment failure; Sperm count; Acrosin; Forecasting

Rimonabant (SR141716) induces metabolism and acquisition of fertilizing ability in human sperm

The endocannabinoid system and the cannabinoid CB(1) receptor have been identified in human sperm, and it is well known that endocannabinoids have pronounced adverse effects on male and female reproduction. In order to elucidate further the pathophysiological role of the endocannabinoid system in male fertility, we investigated the activity of the CB(1) receptor antagonist rimonabant (SR141716) on the fertilizing ability of human sperm. We evaluated in vitro the effects of rimonabant on motility, survival, capacitation, acrosin activity and metabolism of human sperm. Particularly, capacitation was studied by using three different approaches: intracellular free Ca(2+) content assay, cholesterol efflux assay and protein tyrosine phosphorylation analysis. Rimonabant significantly increased sperm motility and viability through the induction of pAkt and pBcl2, key proteins of cell survival and metabolism, and it induced acrosome reaction and capacitation as well. Rimonabant reduced the triglyceride content of sperm, while enhancing lipase and acyl-CoA dehydrogenase activities, implying an overall lipolytic action in these cells. Rimonabant also affected sperm glucose metabolism by decreasing phosphorylation of glycogen synthase kinase 3 and increasing glucose-6-phosphate dehydrogenase activity, suggesting a role in inducing sperm energy expenditure. Intriguingly, agonism at the CB(1) receptor, with an anandamide analogue or a selective inhibitor of fatty acid amide hydrolase, produced opposing effects on human sperm functions. Our data suggest that blockade of the CB(1) receptor by rimonabant induces the acquisition of fertilizing ability and stimulates energy expenditure in human sperm.

Relationship of acrosin activity to sperm function tests.

Acrosin activity of spermatozoa from infertile patients and fertile volunteers was measured. Acrosin activity of spermatozoa from asthenozoospermic patients and patients with unexplained infertility was lower than that from fertile volunteers. We utilize the zona-free hamster egg-sperm penetration test to select candidates for conventional in vitro fertilization among unexplained infertile patients. The zona-free hamster egg sperm penetration test, however, requires several hours and special equipment which are not used in the clinical setting. It is preferable that other sperm function tests or a combination of them can replace this test. Thus three distinct tests of sperm function, namely, acrosin activity, Penetrak test, hypo-osmotic swelling test, were compared with the hamster test, using spermatozoa from patients with unexplained infertility. A combination of the Penetrak test and measurement of acrosin activity could predict the results of the zona-free hamster egg sperm penetration test with 88.2% accuracy. Thus, the hamster test should be done when either Penetrak test or measurement of acrosin activity showed abnormal values.

Relation of human sperm acrosin activity and fertilization in vitro.

The aim of the study described here was to determine the possible contribution of the acrosin activity test to routine semen analysis in enhancing the precision of the prognosis of IVF success in a group of patients in which the contribution of the egg factor to infertility was ruled out (20 cases) compared to a control IVF group (39 cases). Semen analysis, acrosin activity and acrosome ultrastructure were determined for all semen samples. The group with high fertilization rates was comprised of normozoospermic patients while the group with low fertilization rates was comprised of astheno-teratozoospermic patients. The mean acrosin level of the positive IVF group was significantly higher than that of the negative group (51.7 +/- 33.2 and 28.6 +/- 13.7, respectively). Two parameters: per cent motile spermatozoa and acrosin level, were found to have a significant positive correlation with subsequent successful IVF (r = 0.36, P < 0.006; r = 0.37, P < 0.004, respectively); and agenesis of the acrosome was found to have a significant negative correlation (r = -0.33, P < 0.01). The ability of these parameters to correctly predict fertilization success was 59%, with 5% false positive, among which 15.4% was predicted solely by the acrosin level (above 54 microIU 10(6) cells-1) and 23% solely by per cent motile spermatozoa (above 50%). Abnormalities of the acrosome ultrastructure did not contribute further to the correct classification. The apparent clinical benefit of the acrosin level test is discussed.

Low acrosin activity in polyzoospermia.

Compared to normozoospermic men total sperm acrosin activity is considerably decreased (-59,1%) in patients with polyzoospermia indicating a functional defect of the proteolytic potential of the sperm acrosome, which may be responsible for the reduced fertility observed in this group of patients.

Acrosin activity in spermatozoa of infertile Nigerian males

The objective of this study was to evaluate acrosin activity in spermatozoa of infertile Nigerian men and to compare with those of the fertile men. The acrosin activity was evaluated using the Acroscreen reagent kit. The acrosin activity of the fertile men was 40.7±5.2 mIU/10(6) sperm (range 30.1-51.3) and those of the infertile men was 22.4±8.33 mIU/10(6) sperm (range 5.7-39.1). The difference in the mean was statistically significant (P<0.001). There was a subpopulation of the infertile men who had their acrosin activity within normal range of the fertile men, 32.9±1.57 mIU/10(6) sperm. But the difference in the mean was statistically significant (P<0.001). Acrosin activity decreased with increased morphological changes in the spermatozoa. It is concluded that acrosin activity in the infertile Nigerian men is significantly lower than that in the fertile men. Acrosin activity may also be affected by morphological changes in the spermatozoa.

Discrepancy between sperm acrosin activity and sperm morphology: significance for fertilization in vitro

Background In routine semen analysis, discrepancies may occur between sperm acrosin activity test results and sperm acrosomal morphology. Methods Discrepant test results of sperm acrosin activity (spectrophotometric assay) vs. sperm morphology (strict criteria) in the initial diagnostic investigation of 107 infertile couples were evaluated with respect to fertilization rate (% oocytes with 2 pronuclei) further obtained in IVF treatment. Results Acrosin activity positively correlated with sperm morphology (% normal forms) ( r=0.537) and fertilization rate ( r=0.526). ROC curves for the prediction of ≥50% fertilization rate were comparable for acrosin activity and sperm morphology, with optimal cutoff values at 25 μIU/10 6 sperm and 10%, respectively. In multiple regression analysis, sperm acrosin activity ( P=0.002) predicted fertilization rate independently of sperm morphology ( P<0.001) and sperm vitality (eosin–nigrosin stain) ( P=0.03). Acrosin activities ≥25 μIU/10 6 sperm were observed in 36% of severe teratozoospermic samples (≤4% normal spermatozoa) associated with low fertilization rate. Twenty percent of the morphologically normal ejaculates showed a low acrosin activity (<25 μIU/10 6 sperm) and low hypoosmotic swelling test (HOST) scores (31.4±7.6%) and were associated with low fertilization rate. Conclusion The sperm acrosin assay can help to predict sperm fertilizing capacity in IVF independently of sperm morphology.

Acrosome activity is lower in sperm from men with spinal cord injury compared to age-matched, healthy control subjects

Objective: Men with spinal cord injury have poor semen quality. While their sperm concentrations tend to be similar to that of normal men, their sperm motility and sperm viability are below average. Conflicting data exist regarding the fertilization potential of sperm from men with spinal cord injury. Among the several tests available to determine spermatozoa’s sperm function and fertilization potential, the acrosome reaction test is relatively simple, inexpensive, reproducible, and has been correlated with subfertility, infertility, and in-vitro fertilization success rates. The goal of this study was to compare acrosin activity in sperm from men with spinal cord injury versus age-matched healthy control subjects. A commercially available acrosome reaction test, the Acroscreen™ assay, was used for this purpose. This assay measures the total acrosin activity in spermatozoa. Design: A between-subjects design was used to compare acrosin activity in subjects with spinal cord injury versus age-matched healthy control subjects. Materials and Methods: Semen samples from 5 subjects with spinal cord injury (mean age in years: 33 ± 2.7 standard error of the mean) and 7 control subjects (37 ± 3.4 years) were measured for acrosin activity using the Acroscreen™ photometric enzyme method. In an IRB-approved protocol, semen was collected from men with spinal cord injury by the standard methods of penile vibratory stimulation (n = 4), or electroejaculation (n = 1). Control subjects produced semen specimens by masturbation. Specimens were first processed on standard PureSperm 40/80™ gradients to remove seminal plasma, which contains protease inhibitors, and other cellular debris. The acrosin activity for the processed specimens was then calculated using optical densities obtained by the photometric enzyme method described in the Acroscreen™ kit. Mean acrosin activity for subjects with spinal cord injury was compared to that of control subjects using analysis of variance. Results: The mean acrosin activity in μIU acrosin/million sperm, was 106.3 ± 29.6 for subjects with spinal cord injury and 215.5 ± 35.2 for control subjects (p < 0.05). Conclusion: The sperm of men with spinal cord injury exhibit significantly less acrosin activity compared to normal controls, indicating a potential lowered fertilization capacity of sperm from these patients. Supported by: the State of Florida Specific Appropriations and the Miami Project to Cure Paralysis.

Effects of Shao-Fu-Zhu-Yu-Tang on motility of human sperm.

Shao-Fu-Zhu-Yu-Tang (SFZYT) is reportedly beneficial to sperm. In this study, we examined sperm acrosomal activity and serum free radical changes to evaluate the possible mechanism of SFZYT. A clinical study evaluated the sperm count and motility in 36 patients with chronic prostatitis before and after treatment for 60 days. The results revealed a significant increase in sperm motility after treatment as evaluated by computer-assisted semen analysis (17.27 +/- 9.00 versus 28.29 +/- 10.00, p < 0.01). An increase in sperm quantity and quality was observed by count and morphology with a high-powered intravital microscope. To gain an understanding of the mechanisms that caused this effect, we assessed sperm acrosin activity levels before (10.6 micro lu/10(6)) and after medication (28.6 micro lu/10(6)) (p < 0.01). The levels of the free radicals was relatively higher before medication, 2144, compared to a normal value of 780 after medication (p < 0.01). In conclusion, SFZYT increased the motility and quality of human semen and this increase is related to an increase in sperm acrosin activity. SFZYT also works as a sperm antioxidant and antiaging agent.

Dexamethasone reduces acrosin activity of ram spermatozoa.

The aim of this study was to investigate the effect of dexamethasone on acrosin activity of spermatozoa in Chios rams during autumn (breeding season for sheep in Greece), in correlation with possible changes in blood testosterone. Dexamethasone was administered in four equal consecutive intramuscular injections, one every four hours (total dose: 3 mg kg(-1)). Total acrosin activity was determined in semen samples collected 48 h before and on the 4th and 7th day and thereafter once every week until the 77th day after dexamethasone administration. Blood samples for testosterone radioimmunoassays were collected 24 h before, during dexamethasone administration and on the 4th, 7th, 14th and 21st day after administration. Total acrosin activity in spermatozoa was reduced between days 7-28 after dexamethasone administration. Dexamethasone also induced a reduction in mean value and basal level of blood testosterone and inhibited its episodic secretion between 1 and 4 days after administration. As the reduction of acrosin activity appeared relatively soon after dexamethasone administration (7th day), it is likely that the increased amount of dexamethasone did not influence the synthesis of proacrosin in the late spermatids. As glucocorticoid receptors exist in the epididymis and accessory glands in various species, dexamethasone may have a direct influence on the synthesis and/or release of acrosin inhibitors in epididymal fluid or seminal plasma. These changes in acrosin activity in ovine spermatozoa mediated by dexamethasone may be of importance regarding the role of stress in the reduction of sperm fertilizing ability.

Effects of season and breed on sperm acrosin activity and semen quality of boars

Acrosin activity and semen quality (sperm concentration, ejaculate volume and number of spermatozoa) were assessed from March 1997 to March 1998 in semen of Large White, Pietrain and Duroc×Pietrain boars. Semen quality varied with season, including high production of spermatozoa in autumn and winter and low production in summer. Semen quality also differed across breeds. Acrosin activity of boar spermatozoa was not affected by breed (range 3.16–3.32mU/106 spermatozoa), but exhibited distinct seasonal changes. Monthly changes in acrosin activity were parallel to changes in number of sperm in the ejaculate from November to March. On the other hand, dramatic changes in acrosin activity between July and October (range 1.85–4.59mU/106 spermatozoa) were not paralleled by similar changes in number of ejaculated sperm. These fluctuations in acrosin activity may reflect either changes in sperm acrosin production or disturbances to sperm membranes, probably related to effects of high summer temperatures during spermatogenesis. Results confirmed seasonal and breed-related differences in boar semen quality characteristics.

The effect of melatonin implants on blood testosterone and acrosin activity in spermatozoa of the ram.

In a series of consecutive blood sampling in 15 days intervals over 15 weeks after implantation of melatonin in rams an increased mean value, basal level and number of peaks of testosterone was observed in samples of the third fortnight (45th day). This increase was greater in the autumn (breeding season) than in spring (non-breeding season). Total acrosin activity in spermatozoa was increased between days 35-56 (autumn) and days 49-70 (spring) after implantation and the relative increase was higher in autumn than in spring. The increase of acrosin activity was independent of the changes of testosterone. An increase of acrosin activity by melatonin, in cases of low activity, might improve fertilization rates in sheep not only during the breeding season, but also during the non-breeding season (after oestrus induction).

P-031. A prospective analysis of the diagnostic value of the semen profile, TEST-yolk buffer enhanced sperm penetration assay, acrosin activity and nuclear maturity test in assessing male fertility

P-031. A prospective analysis of the diagnostic value of the semen profile, TEST-yolk buffer enhanced sperm penetration assay, acrosin activity and nuclear maturity test in assessing male fertility

Assay of sperm acrosin activity and its clinical application : contrast of activity in testis, epididymis and analysis of human sperm acrosin and its affecting factors

Assay of sperm acrosin activity and its clinical application : contrast of activity in testis, epididymis and analysis of human sperm acrosin and its affecting factors

Characterization of acrosin‐like activity of lake sturgeon (Acipenser fulvescens) spermatozoa

Acipenserid fish sperm possess trypsin-like activity, resembling acrosin activity of mammalian sperm, which can be measured by hydrolysis of N-α-benzoyl-DL-arginine p-nitroanilide (BAPNA) Ciereszko et al., 1994: J Exp Zool 268:486–491). We found that this activity can be preserved when sperm is frozen on dry ice with 0.6 M sucrose-10% dimethylsulfoxide (DMSO) extender (sperm:extender ratio 1:3), and subsequently stored in liquid nitrogen. However, other methods of freezing (without cryoprotectant at −18°C, −80°C, and −196°C) did not protect this activity. Acrosin-like activity decreased in the course of storage of milt on ice; 88% decline was recorded after 13 days. Acrosin-like activity increased with temperature from 10°C to 30°C, but was inactivated at 40°C to about 40% as compared to the optimum temperature. Triton X-100 inhibited activity by 15% and 72% at 0.01% and 0.1% concentrations, respectively. Activity was not affected by Mg2+ but was inhibited by Zn2+ (30% and 75% in the presence of 0.1 mM and 1 mM, respectively). Maximum velocity of substrate hydrolysis was observed at 2 mM of BAPNA. Acrosin-like activity was effectively inhibited by 4′-acetamidopheny1 4-guanidinobenzoate (AGB), an inhibitor of mammalian acrosin. Sperm acrosin-like activity correlated negatively with anti-proteinase activity of seminal plasma. We conclude that sturgeon acrosin-like activity shares many properties with mammalian acrosin. On the other hand, it has some unique properties which may represent adaptations of this enzyme to the environment of external fertilization. © 1996 Wiley-Liss, Inc.

Characterization of acrosin-like activity of lake sturgeon (Acipenser fulvescens) spermatozoa.

Acipenserid fish sperm possess trypsin-like activity, resembling acrosin activity of mammalian sperm, which can be measured by hydrolysis of N-alpha-benzoyl-DL-arginine p-nitroanilide (BAPNA) (Ciereszko et al., 1994: J Exp Zool 268:486-491). We found that this activity can be preserved when sperm is frozen on dry ice with 0.6 M sucrose-10% dimethylsulfoxide (DMSO) extender (sperm:extender ratio 1:3), and subsequently stored in liquid nitrogen. However, other methods of freezing (without cryoprotectant at -18 degrees C, -80 degrees C, and -196 degrees C) did not protect this activity. Acrosin-like activity decreased in the course of storage of milt on ice; 88% decline was recorded after 13 days. Acrosin-like activity increased with temperature from 10 degrees C to 30 degrees C, but was inactivated at 40 degrees C to about 40% as compared to the optimum temperature. Triton X-100 inhibited activity by 15% and 72% at 0.01% and 0.1% concentrations, respectively. Activity was not affected by Mg2+ but was inhibited by Zn2+ (30% and 75% in the presence of 0.1 mM and 1 mM, respectively). Maximum velocity of substrate hydrolysis was observed at 2 mM of BAPNA. Acrosin-like activity was effectively inhibited by 4'-acetamidophenyl 4-guanidinobenzoate (AGB), an inhibitor of mammalian acrosin. Sperm acrosin-like activity correlated negatively with antiproteinase activity of seminal plasma. We conclude that sturgeon acrosin-like activity shares many properties with mammalian acrosin. On the other hand, it has some unique properties which may represent adaptations of this enzyme to the environment of external fertilization.

Acrosomal morphology as a novel criterion for male fertility diagnosis: relation with acrosin activity, morphology (strict criteria), and fertilization in vitro

To determine the relationships between sperm acrosin activity, sperm morphology evaluated according to strict criteria, visually observed acrosomal morphology, and IVF rates. Prospective analytic study. Acrosin activity was determined on all semen samples together with a standard semen analysis. Emphasis was placed on sperm morphology and especially a novel criterion viz acrosome morphology (acrosome index) as recorded with bright field microscopy. University-based tertiary care center. Thirty-three couples undergoing IVF or GIFT with two or more metaphase II ova inseminated in vitro. In vitro fertilization rates of inseminated ova. Strong correlations were found between acrosome index, normal sperm morphology, and IVF rates. An acrosome index cutoff value could be established at > 10% normal acrosomes for IVF rates of > or = 50% (sensitivity and specificity = 100%) and an acrosin activity cutoff value at > 18 microIU/10(6) sperm. A multiple linear regression analysis showed that the acrosome index and acrosin activity added a significant contribution to the explanation of the variation in the fertilization rates. A strong positive correlation was found between acrosome index and IVF rates. Although the numbers of the study are small, the results indicate that the acrosome index possibly may be regarded as an additional tool in the prediction of IVF outcome and especially may be of value in the group of men with severe teratozoospermia, i.e., < or = 4% morphologically normal spermatozoa.

The effect of smoking and varicocele on human sperm acrosin activity and acrosome reaction.

Smoking and varicocele are frequent findings in the medical history and physical examination of patients attending andrological outpatient departments. However, data about their influence on human semen parameters, such as sperm concentration and motility, are contradictory. Therefore, the purpose of this study was to examine sperm function (acrosin activity and induction of the acrosome reaction) in smokers (n = 30) and varicocele patients (n = 30) compared with normal fertile donors (n = 20). The acrosome reaction was detected by triple staining after 3 h of incubation at 37 degrees C, followed by treatment with 0.1% dimethylsulphoxide (spontaneous acrosome reaction) and 10 microM calcium ionophore A23187 (induced acrosome reaction) for 1 h at 37 degrees C. Acrosin activity was measured by gelatinolysis. The diameters around the sperm heads after gelatinolysis and the percentages of spermatozoa showing halo formations were evaluated. The inducibility of the acrosome reaction was significantly lower in semen samples from smokers than in those from the fertile group (7.1 +/- 3.2 versus 11.2 +/- 4.0%, P < 0.01), whereas no statistically significant difference was demonstrated in spermatozoa from patients with varicocele (9.3 +/- 4.3%). Both the percentages of spermatozoa with halo formation (53.3 +/- 20.0 versus 76.6 +/- 13.6%, P < 0.05) and the halo diameters (16.1 +/- 6.6 versus 31.0 +/- 14.5 microns, P < 0.001) were significantly lower in the varicocele group than in the samples from fertile men. These data suggest that smoking and varicocele affect sperm function, and that the standard semen parameters alone are insufficient to evaluate the influence of both factors on human male fertility.

Impaired hamster egg penetration by human sperm from ejaculates with low acrosin activity but otherwise normal

To determine if a low acrosin activity in otherwise normal ejaculate from infertile patients is associated with an impairment of sperm functions involved in the hamster egg penetration. A tertiary care center, the Andrology Clinic, Department of Internal Medicine, University of L'Aquila. Nine infertile patients with low acrosin activity in otherwise normal ejaculate (including normal immunoreactivity for acrosin) were studied; nine fertile men served as a control group. The two groups were homogeneous for seminal parameters. The hamster egg penetration assay and the acrosome reaction rate assessment were performed on capacitated sperm suspensions in basal conditions and after ionophore challenge. The penetration rate, the penetration index, and the acrosome reaction rate were measured and compared between the groups. No penetration was achieved in seven patients and a low penetration was achieved in two cases. The difference with the control group was significant. The ionophore challenge was associated to penetration of hamster eggs in seven of nine patients, but the penetration index was significantly lower than the controls. Acrosin activity was correlated to hamster egg penetration. Both spontaneous and induced acrosome reaction rate were similar in the two groups. A low sperm acrosin activity in otherwise normal ejaculate is associated with an impaired hamster egg penetration. This impairment does not seem to be due to altered dynamics of acrosome reaction.