The Release of Hyaluronidase From Guinea-Pig Spermatozoa During the Course of the Normal Acrosome Reaction in Vitro

Hamster spermatozoa incubated in heat-pretreated blood serum release 55 to 60% of their total hyaluronidase activity by the end of 1 hr of incubation; little increase in activity is found in the incubation medium at later time intervals up to 4 hr (Rogers & Morton, 1973; Talbot & Franklin, 1974b). This release occurs well before and independently of a normal acrosome reaction, i.e. detachment of the acrosome from motile spermatozoa as observed with phase-contrast microscopy (Talbot & Franklin, 1974b). Vesiculation between the outer acrosomal membrane and plasma membrane does not occur before the surge of hyaluronidase release which takes place between time zero and 1 hr of incubation (Talbot & Franklin, 1974b). Lewis & Ketchel (1972a, 1973) demonstrated that the release of hyaluronidase from rabbit spermatozoa incubated in postovulatory uterine fluid is "related to the completion