Components of human split ejaculates. II. Enzymes and proteinase inhibitors

Lysozyme, alpha-amylase, neutral proteinase and plasminogen activator were most concentrated in the initial portion of the ejaculate that consists mostly of Cowper's gland and prostate gland fluids as well as spermatozoa. The concentration of the high molecular weight proteinase inhibitors, alpha1-antitrypsin and alpha1X-antichymotrypsin, was essentially unaltered throughout the ejaculate fractions, although their absolute amounts showed an increase towards the final fraction. By contrast, the total inhibitory activity towards pancreatic trypsin was highest both in concentration and amount in the last fraction, thus indicating that the seminal vesicles are its primary source. Plasminogen, prothrombin, Factor XIII, and the proteinase inhibitors antithrombin III, alpha2-macroglobulin, inter-alpha-trypsin inhibitor and C1S-inactivator could not be detected immunochemically in whole ejaculates, and indicates the dissimilarity between the coagulation/liquefaction processes of semen and blood.