Preliminary study of buffalo sperm penetration into zona-free hamster eggs after treatment with calcium ionophore A23187.

A previous study (Takahashi & Hanada, 1984) reported the penetration of zona-free hamster eggs by ejaculated bull spermatozoa after treatment with calcium ionophore A23187 (Ca-IA) in the presence of caffeine. Based on this study, successful IVF was accomplished not only in cattle (Hanada, 1986b) but also in goats and sheep (Hanada, 1986a) using spermatozoa treated with Ca-IA. In the present study, the effectiveness of Ca-IA treatment in inducing the fertilizing capacity of the river buffalo (Bubalus Bubalis) spermatozoa using zona-free hamster eggs, was examined, Modified Krebs-Ringer bicarbonate solution (mKRB ; Toyoda & Chang, 1974) was used for handling hamster oocytes. This medium was also used to make a solution of O.1% hyaluronidase (lyophilised powder from bovine testes, Sigma Chem. Co., St.