Enzymatic sulfation of steroids: I. The enzymatic basis for the sex difference in cortisol sulfation by rat liver preparations.

Liver cytosols from female rats contained 6-8 times as much cortisol sulfotransferase activity as those from males. The reaction product, with both sexes, appeared to be cortisol-21 sulfate. Liver cytosols from male and female rats showed different substrate preferences when tested with cortisol, estradiol-17beta, testosterone, and dehydroepiandrosterone, suggesting that they contained different steroid sulfotransferases. Fractionation of cytosols from female rats on DEAE Sephadex A-50 columns resolved 3 steroid sulfotransferases, or families of steroid sulfotransferases (STI, STII, and STIII). These enzymes exhibited different substrate preferences. STI and STIII had the greatest preferences for cortisol, although none of the enzymes was restricted to the glucocorticoid. Fractionation of cytosols from males resolved 2 sulfotransferases which eluted at salt concentrations identical to STII and STIII from females. Study of the development of cortisol sulfotransferase activity with age showed little enzyme activity in rats of either sex at 2 days after birth. Enzyme activity developed in parallel in both sexes until 30 days after birth. Then the sulfotransferase activity began to rise in females and to drop in males. By day 50-55 both sexes attained adult enzyme levels. STII was the major enzyme in all immature animals. STIII was also present, but STI was absent. In male rats STIII activity began to rise by day 30. Soon after, STII activity began to drop. By day 55 adult male patterns developed. STI was the major enzyme in females by day 30. In ensuing days all 3 enzyme levels rose, until by day 50 adult enzyme patterns and levels were attained. The data suggest that the ovaries stimulated production of all 3 sulfotransferases and that the testes suppressed production of STII (and perhaps STI). Preliminary studies with gonadectomized rats supported the suppressive role of the testes, but suggested that the ovaries were not the only factor controlling sulfotransferase production in female rats.