摘要
以精子穿透去透明带仓鼠卵试验(SPA)为模型,评价了精胺对人精子体外受精能力的影响。精胺(0.25—8.0mmol/L)可抑制人精子体外获能和受精,其抑制作用与精胺浓度呈正相关,此种抑制作用是可逆的。用 HPLC 测定精子精胺含量表明,精子获能后精胺含量明显下降。dbcAMP(0.5—1.0mmol/L)或咖啡因(10mmol/L)可拮抗精胺抑制人精子体外获能。其拮抗作用随 dbcAMP 浓度而增强。钙离子载体 A 23187 2/μmol/L 或胰蛋白酶0.05%均可拮抗精胺抑制人精子穿卵率。上述结果提示,精胺可能通过降低精子 cAMP 含量和抑制钙内流或顶体酶活性,从而阻止人精子体外获能和受精。
The direct effect of spermine at various concentrations(0.25—8.0 mmol/L)on in vitro fertilizing ability of human spermatozoa was evaluated by the penetra-tion test of zona-free hamster egg.To study the effect of spermine on capacitation,as judged by the rate of penetration,spermatozoa were incubated in BWW withvarious concentrations of spermine for 6 h at 37℃.The hyperactivated motilityof spermatozoa was markedly inhibited by spermine at a concentration of 4.0mmol/L.The penetration rate was decreased proportionally to the dose of spermineused.Spermatozoa were incubated in BWW with 0.5 mmol/L spermine for6 h and another 4 h after spermine was washed off with spermine-free BWW.Thepercentage of penetration was comparable to that of the control.Therefore,sper-mine-mediated inhibition of capacitation was reversible.Moreover,exogenousdbcAMP(0.5—1.0 mmol/L)or caffeine(10 mmol/L)could antagonize signi-ficantly the spermine-induced inhibition of capacitation with a correlation co-efficient of 0.990.The content of spermine in fertile men spermatozoa was assayedby HPLC.Before capacitation spermine in spermatozoa was 7.05 μg/10~7 cells,whereas after capacitation it was no longer detectable,indicating that sperminemay be an inhibitor of in vitro capacitation in human sperm.To study the effect ofspermine on capacitated sperm,spermine was added to the BWW medium aftersperm had been preincubated in spermine-free BWW.The persistent presence ofspermine could interfere with spermatozoa attachment to,binding to and penetra-tion into zona-free hamster eggs,which was related to the concentration(r=0.820)used.Ionophore A23187(2μmol/L)or 0.05% trypsin also antagonized speci-fically the inhibition of in vitro fertilization induced by spermine.The results suggest that spermine may be an inhibitory agent of in vitro capaci-tation and fertilization in human sperm,and the inhibitory effect is mediated bydeprivation of cAMP and the suppression of activity of acrosomal enzyme(s)orCa^(2+)influx.
出处
《生理学报》
CAS
CSCD
北大核心
1991年第5期480-488,共9页
Acta Physiologica Sinica
基金
国家自然科学基金
中国科学院生物科学和技术局
美国洛氏基金(GA PS-829)的资助
关键词
精胺
精子
受精
获能
spermine
sperm
capacitation
fertilization
zona-free hamster egg
dbc-AMP
Ionophore A23187
trypsin
