[Studies on in vitro capacitation of goat spermatozoa by heparin treatment].
摘要
Systematical studies are lacking on the influencing factors and mechanisms of the heparin enhanced sperm capacitation, although many studies have shown that heparin enhanced sperm capacitation. The effect of heparin concentration and exposure time, incubation temperature and co-culture with oviductal epithelial cells or cumulus cells on goat sperm capacitation were investigated in this study. The motility, membrane and acrosome integrity and capacitated percentage of goat spermatozoa were assessed after different heparin treatments, and rates of fertilization and embryo cleavage were compared after in vitro insemination of oocytes with spermatozoa capacitated by different heparin treatments. The major results are summarized as follows: 1) When spermatozoa were capacitated with heparin at 5, 10, 25, 50 and 100 microg/mL for 45 min, 50 and 100 microg/mL heparin treatments produced the highest capacitated percentages of 55% and 56%, respectively, but the percentage of spermatozoa with intact acrosomes in the 100 microg/mL heparin treatment decreased significantly (P < 0.05) in comparison with that in the control group, indicating that the optimal heparin concentration for goat sperm capacitation would be 50 microg/mL. 2) Capacitated percentage of spermatozoa increased with extension of treatment time when goat sperm were treated with 50 microg/mL heparin for 0, 10, 20, 30, 45, 60 or 120 min. Although heparin treatments for 45 to 120 min did not differ significantly (P > 0.05) in capacitated sperm percentages, sperm motility and membrane integrity decreased significantly when treated with heparin for 120 min. This suggested that the optimal exposure time of heparin at 50 microg/mL for goat sperm capacitation would be 45 to 60 min. 3) Significantly higher capacitated percentages of spermatozoa were obtained when goat sperm were treated at 42 and 38.5 degrees C than at 15 and 37 degrees C, but sperm motility and acrosome integrity were significantly lower when spermatozoa