The Effects of Cauda Epididymal Plasma on the Motility and Acrosome Reaction of Hamster and Guinea Pig Spermatozoa in vitro

Abstract
Hamster cauda epididymal plasma (CEP) was found to sustain the motility of hamster epididymal spermatozoa in vitro. The active component was stable to boiling and its elution volume on Sephadex G-10 was identical to that of the heat stable sperm motility factor (SMF) found in several other body tissues and fluids, including spermatozoa. The sperm motility stimulating activity in hamster CEP may be due to the presence of SMF, which could thus serve to maintain adequate levels of SMF within cauda epididymal spermatozoa. Inclusion of hamster CEP in the culture medium inhibited the acrosome reaction of hamster and guinea pig spermatozoa in vitro. Inhibitory activity was not lost following dialysis. Inhibitory substances present in hamster CEP may be 1-means by which the environment within the male reproductive tract is rendered unfavorable for the occurrence of acrosome reactions.