IDENTIFICATION OF THE HUMAN SEMINAL TRH-LIKE PEPTIDE PGLU-PHE-PRO-NH2IN NORMAL HUMAN PROSTATE

Human and rat prostate contain thyrotropin-releasing hormone immunorea ctivity (iTRH) including TRH and an uncharged TRH-like peptide. Recent ly the uncharged TRH-like peptide pGlu-Phe-Pro-NH2 was purified from h uman semen. To determine whether this peptide was of prostatic origin, human and rat prostate extracts were analyzed by ion-exchange chromat ography and reversed-phase HPLC. The predominant uncharged iTRH comigr ated exactly with synthetic pGlu-Phe-Pro-NH2 on HPLC and had identical affinity to pGlu-Phe-Pro-NH2 in a TRH radioimmunoassay. We conclude t hat prostate is a source of this peptide in humans and rats. This amid ated TRH-like peptide may play a role in human reproductive physiology .