The relationship between the immunosuppressive and cytotoxic effects of human seminal plasma.

This report describes the cytotoxic properties of human seminal plasma and demonstrates that the inhibition of response to mitogens shown by murine lymphocytes in the presence of whole human seminal plasma can be attributed largely to an effect of seminal components on lymphocyte viability. It is hypothesised that the cytotoxic effect of seminal plasma arises as a result of the oxidation of spermine in seminal plasma by an amine oxidase enzyme present in fetal calf serum. In support of this hypothesis, it was found that seminal plasma cytotoxicity is serum dependent and is inhibited in the presence of the amine oxidase inhibitor hydroxylamine.