Distribution of acrosin inhibitors in bull reproductive tissues and spermatozoa.

Antisera against two low molecular weight acrosin inhibitors, isolated from bull seminal plasma (BUSI I and BUSI II), were prepared by immunizing rabbits and hamsters. Antisera to BUSI I and BUSI II cross-reacted immunologically with low intensity. Using immunological techniques BUSI I and BUSI II could be demonstrated in the tissues and fluids of bull seminal vesicles and ampullae and on the acrosomes of ejaculated and ampullar spermatozoa. BUSI II was also detected in the epididymal fluid and on the acrosomes of epididymal spermatozoa. Antisera to both inhibitors cross-reacted with boar seminal vesicle fluid and ram seminal plasma. There was no cross-reaction with the components of blood serum.