Localization of prostaglandin on the plasmalemma of rabbit sperm

Prostaglandin and prostaglandin receptors were localized on unwashed ejaculate rabbit sperm utilizing ferritin conjugated antibody to prostaglandin. Reaction was obtained over the acrosomal portion of the plasma membrane, with a greater aggregation over the apex of the head. The remainder of the head plasmalemma and flagellum showed no deposits of reaction product. The reaction did not occur if the sperm were washed prior to incubation with the labelled antisera. However enhanced binding of ferritin was demonstrated if washed sperm were pre‐incubated in PGE1. No reaction was seen in similar studies with human sperm.