Levels of plasma c19 steroids and 5[alpha]-reduced c19 steroid glucuronides in primates, rodents and domestic animals. Guillemette, Chantal, Dean W. Hum, and Alain B[acute]elanger. MRC Group in Molecular Endocrinology, CHUL Research Center and Laval University, Quebec, G1V 4G2, Canada
APStracts 3:0086E, 1996.
In this study, a comparison of circulating levels of ADT-G and 3[alpha]-DIOL-G in the male and female of several mammalian species was performed. Glucuronidated steroids were not detected in the circulation of the dog, bovine, porcine and rodent. High levels of circulating glucuronidated steroids were measured in Cynomolgus monkey and were 10-fold higher than in human. The determination of tissue levels of unconjugated and conjugated C19steroids was then performed in intact and castrated rats treated with androgens. Steroid glucuronides were not detected in the plasma, skin, prostate and liver of both intact and treated rats although the levels of unconjugated steroids in the plasma and tissues were increased following steroid treatments. Significant levels were detected in the bile thus suggesting hepatic formation of steroid glucuronides in the rat. It is suggested that the monkey represents the best animal model to date to study the contribution of UGTs, present in steroid target peripheral tissues, to circulating levels of steroid glucuronides.

Received 18 October 1995; accepted in final form 1 April 1996.
APS Manuscript Number E500-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 1 May 96