16-Hydroxylation of Estrone-3-Sulfate and Estrone in the Guinea Pig in Vivo*

Abstract

[6,7-3H]Estrone-3-sulfate or [6,7-3H]-estrone of high specific activity was injected into adult female English Shorthair guinea pigs. Blood, liver, kidney, gall bladder bile, and urine were obtained and investigated for metabolites. Chromatographic procedures followed by enzymatic or solvolytic cleavage of conjugates and subsequent crystallization with appropriate carrier steroids revealed the pattern of metabolites formed. Injected estrone sulfate was partially hydrolyzed and reconjugated, resulting in the production of estrone and estradiol glucuronides. The main metabolites, however, were monosulfates of 16alpha-hydroxyestrone, 16-keto-17beta-estradiol, and estriol as well as disulfates of 16alpha-hydroxyestrone, estriol, and 16beta-hydroxyestrone. Particularly high amounts of these were found in urine. By far the main metabolites of injected estrone were glucuronides of estrone and estradiol, although the pattern of mono- and disulfated steroids was qualitatively similar to that found after estrone sulfate injection. It is concluded that the guinea pigs employed in the study hydroxylated estrogen in the 16alpha- and 16beta-configurations and that this activity was much more pronounced after injection of estrone sulfate than after estrone.

A reliable radiochromatographic assay technique for hepatic microsomal 16 α-hydroxylase activity towards oestrone 3-sulphate. Comparison between pigmented and non-pigmented mature guinea pigs

“…Evidence in vivo has been reported for the 16 a-hydroxylation of oestrogens in pigmented female guinea pigs (Hobkirk et al, 1978). Recently, experiments in vivo from our own laboratory, on albino guinea pigs, have suggested a relationship between the ability to hydroxylate oestrogens and pigmentation of the animals.…”