Inhibition of PHA-stimulated proliferation of peripheral blood mononuclear cells by human seminal plasma inhibin (HSPI).

This report deals with the effect of purified HSPI (10.7 kDa single chain prostatic peptide of 94 amino acids) on PHA-stimulated proliferation of peripheral blood mononuclear cells (PBMNC). HSPI was found to inhibit the incorporation of 3H-thymidine by PHA-stimulated PBMNC in a dose-dependent manner, albeit with the requisite of pretreatment of cells with HSPI. A maximum inhibition was observed on pretreatment for 30 min. These studies thus indicate that HSPI may be interfering with the very early events of PHA-induced signal transduction process in PBMNC.