De Jonge C J, Mack S R, Zaneveld L J
Department of Obstetrics and Gynecology, Rush University, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612-3864.
Gamete Res. 1989 Aug;23(4):387-97. doi: 10.1002/mrd.1120230404.
The analogue of the second messenger cAMP, dibutyryl cAMP (dbcAMP), was shown to induce the human sperm acrosome reaction to the same extent as calcium ionophore A23187, providing preliminary evidence for the involvement of the adenylate cyclase system in the acrosome reaction (AR) of human spermatozoa. Using the human synchronous acrosome reaction system, proteinase inhibitors were tested for their effect on the dbcAMP-induced human sperm acrosome reaction. The proteinase inhibitor 4'-acetamidophenyl 4-guanidinobenzoate (AGB), an inhibitor of proacrosin activation and of acrosin, when added at either the onset of incubation or to capacitated spermatozoa, 5 min prior to stimulation by dbcAMP, significantly (P less than 0.01) inhibited the acrosome reaction at final concentrations of 1 x 10(-4) M to 1 x 10(-6) M in comparison to dbcAMP treatment alone. At concentrations less than 1 x 10(-6) M, no significant inhibitory effect was seen. Similarly, para-aminobenzamidine (pAB), also an inhibitor of proacrosin activation and of acrosin, significantly (P less than 0.01) inhibited the dbcAMP-induced acrosome reaction at final concentrations of 1 x 10(-4) M to 1 x 10(-6) M when added at either the onset of incubation or to capacitated spermatozoa, 5 min prior to stimulation by dbcAMP, in comparison to stimulation by dbcAMP alone. However, at concentrations less than 1 x 10(-6) M, no significant (P greater than 0.05) inhibitory effect was seen. These results indicate that a serine proteinase, most likely acrosin, has a role in the human sperm acrosome reaction and suggest that the enzyme functions after the involvement of the adenylate cyclase system.
第二信使环磷酸腺苷（cAMP）的类似物二丁酰环磷腺苷（dbcAMP）已被证明可诱导人类精子顶体反应，其程度与钙离子载体A23187相同，这为腺苷酸环化酶系统参与人类精子顶体反应（AR）提供了初步证据。利用人类同步顶体反应系统，测试了蛋白酶抑制剂对dbcAMP诱导的人类精子顶体反应的影响。蛋白酶抑制剂4'-乙酰氨基苯基4-胍基苯甲酸酯（AGB）是一种前顶体蛋白酶激活和顶体蛋白酶的抑制剂，在孵育开始时或在dbcAMP刺激前5分钟添加到获能精子中，与单独的dbcAMP处理相比，在终浓度为1×10^(-4) M至1×10^(-6) M时，显著（P<0.01）抑制顶体反应。在浓度低于1×10^(-6) M时，未观察到显著的抑制作用。同样，对氨基苯甲脒（pAB）也是一种前顶体蛋白酶激活和顶体蛋白酶的抑制剂，在孵育开始时或在dbcAMP刺激前5分钟添加到获能精子中，与单独的dbcAMP刺激相比，在终浓度为1×10^(-4) M至1×10^(-6) M时，显著（P<0.01）抑制dbcAMP诱导的顶体反应。然而，在浓度低于1×10^(-6) M时，未观察到显著（P>0.05）的抑制作用。这些结果表明，一种丝氨酸蛋白酶，很可能是顶体蛋白酶，在人类精子顶体反应中起作用，并表明该酶在腺苷酸环化酶系统参与后发挥作用。
