当前位置： SCI文献检索 > MOLECULAR REPRODUCTION AND DEVELOPMENT期刊下所有文献 > Importance of mammalian sperm metalloendoprotease activity during the acrosome reaction to subsequent sperm-egg fusion: inhibitor studies with human sperm and zona-free hamster eggs.

Importance of mammalian sperm metalloendoprotease activity during the acrosome reaction to subsequent sperm-egg fusion: inhibitor studies with human sperm and zona-free hamster eggs.

Abstract：

:We have previously shown that each of the metalloendoprotease (MEP) inhibitors phosphoramidon, diethylenetriaminepentaacetic acid, and carbobenzoxy-L-phenylalanine, when present only during the human sperm acrosome reaction (AR), will not inhibit the AR or sperm motility but will decrease the number of sperm that penetrate zona-free hamster eggs. The present study was designed to investigate whether this inhibition of penetration is due to an effect on sperm binding to the egg plasma membrane and/or to an effect on the actual membrane fusion event. In these studies we used ionomycin to initiate the AR and assayed binding in a Ca(2+)-free medium and fusion in Ca(2+)-containing medium in the same experiment. Eggs were loaded with the fluorescent dye Hoechst 33342, and the appearance of fluorescence in a sperm head indicated that fusion had occurred. The three MEP inhibitors reduced binding only slightly but inhibited the actual fusion step by 50-60% (determined with an equation that corrected for any inhibition of fusion due to inhibition of binding). MEP inhibitors present only during gamete interactions had little or no effect on fusion. We also found that phosphoramidon-inhibitable MEP activity was released during the ionomycin-initiated AR. Incubation of AR supernatant containing MEP activity with previously acrosome-reacted, phosphoramidon-treated sperm resulted in a large reversal of the phosphoramidon-inhibitory effect on sperm-egg fusion. These results support the hypothesis that the acrosomal phosphoramidon-inhibitable MEP released during the AR acts directly or indirectly during that event to increase the fusibility of the sperm plasma membrane region required for subsequent sperm-egg fusion.

journal_name

Mol Reprod Dev

journal_title

Molecular reproduction and development

authors

Díaz-Pérez E,Meizel S

doi

10.1002/mrd.1080310206

keywords:

subject

Has Abstract

pub_date

1992-02-01 00:00:00

pages

122-30

issue

eissn

1040-452X

issn

1098-2795

journal_volume

pub_type

杂志文章

在线工具

Importance of mammalian sperm metalloendoprotease activity during the acrosome reaction to subsequent sperm-egg fusion: inhibitor studies with human sperm and zona-free hamster eggs.