Hoshi K, Saito A, Suzuki M, Hayashi K, Yanagimachi R
Nihon Sanka Fujinka Gakkai Zasshi. 1982 Nov;34(11):1899-906.
Effects of Ca++ and Mg++ on human fertilization were investigated. For this study, in vitro fertilization assay employing the zona-free hamster eggs and the salt-stored human eggs were used. In Ca++ & Mg++-free medium, human spermatozoa could not penetrate into zona-free hamster egg. Sperm penetration occurred in Ca++-free medium containing Mg++ (1.19mM greater than or equal to) indicating that Mg++ can substitute for Ca++ although this was less effective than Ca++. In Ca++-free medium, human spermatozoa could not penetrate into zona pellucida of salt-stored human egg. These results suggest that Ca++ and Mg++ are essential for acrosome reaction of human spermatozoa. And, in Ca++ & Mg++-free medium, acrosome reacted human spermatozoa could not penetrate into zona-free hamster egg. This result indicates that Ca++ and Mg++ are essential for sperm-egg fusion, too.