A NEWLY DISCOVERED ROLE FOR COWPER'S GLAND SECRETION IN RODENT SEMEN COAGULATION

Abstract

Summary. When rat Cowper's (bulbo-urethral) secretion was reacted in vitro with vesicular secretion, coagulation occurred. The reaction displayed a pH optimum of 5·9. Neither heat nor dialysis of Cowper's secretion destroyed its activity. Electrophoretic fractionation of Cowper's secretion resulted in the isolation of the active fraction which, on the basis of chemical tests, appears to be a glycoprotein. The vesicular substrate for this reaction was identified by electrophoresis. Cowper's secretion of the mouse and hamster was also active in coagulating vesicular secretion, but this gland, in the guinea-pig, was without activity. Electrophoresis of bulbo-urethral secretion demonstrated that the guinea-pig alone lacked the fraction which corresponded to the active agent in the rat. The results indicate that the secretion of the bulbo-urethral glands in the rat, mouse and hamster (but not the guinea-pig) may have a hitherto unrecognized role in the formation of the copulatory plug and subsequent fertility in these species.