Glycoprotein glycosyltransferases in male reproductive organs and their hormonal regulation

The prostate glands of rats, mice, guinea pigs and hamsters were found to be a rich source of enzymes catalyzing the Mn2+-dependent transfer of galactose from UDP-galactose to glycoprotein acceptors such as ovomucoid and ovalbumin. The rat ventral prostate was also very active in promoting transfer of fucose from GDP-fucose to ovomucoid. The prostatic enzymes promoting both galactosyl and fucosyl transfers to glycoproteins were very largely membranebound, and were markedly activated by the non-ionic detergent Triton X-100. Castration of adult male rats resulted in a many-fold and roughly parallel decline in both glycosyltransferase activities over a period of two weeks, which was reversed by subsequent daily treatment with testosterone for 8 days. The very low galactosyltransferase of the ventral prostate of hypophysectomized rats was markedly enhanced by testosterone administration, whereas prolactin alone or in combination with androgen had no significant effect.