Seminal plasma biochemistry II: seminal plasma and spermatozoal cytidine monophosphate-sialic acid synthetase and sialyltransferase activities.

Abstract

The zona pellucida receptor for spermatozoa has not been identified and the mechanism by which spermatozoa traverse the zona pellucida has not been elucidated. It is proposed that the zona pellucida receptor is a glycoprotein and the receptor per se is galactosamine or N-acetyl galactosamine. The mechanism by which spermatozoa transverse the zona pellucida may be by its structural modification, by the transfer of spermatozoal sialic acid. In addition, male infertility resulting from oligozoospermia or polyzoospermia, may be due to lack of spermatozoal bound sialyltransferase. A total of 43 semen samples were examined for cytidine monophosphate-sialic acid synthetase and sialyltransferase activities. It was found that both these enzymes are present in seminal plasma and bound to the spermatozoa. The spermatozoal bound enzymes may be derived from the seminal plasma which may be a limiting factor in terms of infertility.