Stimulation of rhesus monkey (Macaca mulatta) proacrosin activation by oviduct fluid

Pronase-resistant low molecular weight stimulators for the activation of proacrosin to acrosin were found in rhesus monkey oviduct fluid collected before, during and after ovulation, but the presence of high concentrations of acrosin inhibitors before and after ovulation partly masked the stimulation in unfractionated fluid. This low molecular weight fraction of oviduct fluid had no detectable esterase or amidase activity by itself, and the stimulating factors were sensitive to digestion by hyaluronidase and chondroitin ABC lyase and were presumed to be glycosaminoglycans. Heparin and hyaluronic acid had similar effects. The presence of soluble glycosaminoglycans at the site of fertilization suggests that they may have a role in capacitation and fertilization.