Depression of glucuronyltransferase activity by glucocorticoids in adult female mice.

Abstract

Three experiments were conducted to examine the effect of glucocorticoids on glucuronidation in the adult female mouse. In the first experiment, four mice served as controls, while four other mice were each given 80 micrograms triamcinolone acetonide (TA) at 39, 25, 15 and 1 h before they were killed. Liver homogenates from all animals were assayed for activity of uridine diphospho-glucuronyltransferase (UDP-GT). The mean enzymatic activity was 115 and 58 nmol of rho-nitrophenol conjugated to glucuronic acid X h-1 X mg of hepatic protein-1 for control and TA-treated mice, respectively (P less than .01). In Exp. 2, 48 mice were divided randomly into 12 groups, with four groups of controls, and four each treated with either 100 micrograms TA or 100 micrograms dexamethasone (DEX) at -4 and 0 h. All of the mice were given 2.5 mmol phenolphthalein (P) at 0 h. The excretion of free P was similar for all groups: however, mice treated with TA or DEX excreted significantly less P-glucuronide and mice treated with TA excreted significantly less P-sulfate than did the controls. In the third experiment, 30 mice each served as controls or were treated with 80 micrograms TA or 500 micrograms metyrapone (M) at -4 and 0 h. Also at 0 h, animals were given .12, .15, .19, .24 or .29 mg rho-cresol/g of body weight. The LD50 of rho-cresol for the control, TA- and M-treated groups were .19, .15 and .24 mg of rho-cresol/g of body weight.(ABSTRACT TRUNCATED AT 250 WORDS)