ENZYMIC ACTION OF ACROSOMAL PREPARATIONS ON THE RABBIT OVUM IN VITRO

Abstract

Summary. Cell-free enzyme preparations consisting of lipoglycoprotein were obtained from acrosomes of ram, bull and rabbit spermatozoa. The ram and bull preparations showed proteolytic and hyaluronidase activities. Preparations from the three species brought about dispersal of the cumulus oophorus and corona radiata of newly ovulated rabbit eggs. In some cases the zona pellucida was also removed. Iodoacetate and a polyanionic hyaluronidase inhibitor each reduced the denuding activity of the ram preparation and to a lesser extent of the bull preparation. Heating to 100° C also reduced the activity of the ram and bull preparations. It is concluded that proteolytic enzymes in spermatozoa contribute to the denudation of rabbit eggs and probably facilitate penetration of the zona pellucida.