INFLUENCE OF TESTOSTERONE AND AN ANTI-ANDROGEN CYPROTERONE ACETATE ON GLUCURONIDE SYNTHESIS IN RAT LIVER TISSUE

Glucuronide synthesis in vitro is much higher when male rat liver tissue is incubated instead of liver from female animals. This difference is caused by a larger supply of UDP-glucuronic acid in liver tissue of males, which corresponds with a higher activity of UDPG-dehydrogenase. A significant decrease of glucuronide synthesis is induced by castration of the male animals, this change being reversible by treatment of the castrated animals with testosterone. Injection of more than 100 μg testosterone propionate daily results in a slight decrease of glucuronide formation. Addition of testosterone in vitro (10-4 M) decreases the production of o-aminophenyl glucuronide during incubation to 50% of control values. The increase of glucuronide synthesis which has been induced by testosterone can not be inhibited by injection of Cyproterone acetate, which is a very potent anti-androgenic substance. On the other hand, Cyproterone acetate itself has a testosterone like activity, i.e. it stimulates the glucuronide synthesis when it has been given in vivo over 10 days. Therefore, the observation, that Cyproterone does not impair the testosterone induced increase of glucuronide synthesis, can not give the answer to the question whether testosterone itself is responsible for the observed sex difference. © 1969 Springer-Verlag.