IN VITRO ACROSOME REACTION AND CAPACITATION OF GOLDEN HAMSTER SPERMATOZOA BY BOVINE FOLLICULAR FLUID AND ITS FRACTIONS

Unheated bovine follicular fluid is very toxic to hamster spermatozoa. This toxicity is due to the action of globulin or globulin‐like substances in the fluid. When the fluid is pre‐treated at 56°C for about 30 minutes these spermicidal substances are detoxified, and the fluid becomes capable of inducing the acrosome reaction and capacitation of the spermatozoa. Follicular fluid contains two factors responsible for the induction of the acrosome reaction and capacitation of spermatozoa, namely the sperm‐stimulating factor and the acrosome reaction‐inducing factor. An efficient sperm acrosome reaction and capacitation can be accomplished only in the presence of these two factors. The sperm‐stimulating factor is dialyzable and heat‐stable (at 90°C). The acrosome reaction‐inducing factor, on the contrary, is non‐dialyzable and heat‐labile (at 90°C). The relationship between sperm acrosome reaction and capcitation is discussed. Copyright © 1969 Wiley‐Liss, Inc., A Wiley Company