Steroid sulfatase activity in the rat ovary, cultured granulosa cells, and a granulosa cell line

• Published in: The Journal of steroid biochemistry and molecular biology 2000-12, Vol.75 (4), p.245-252
• Main Authors: Clemens, Jeffrey W, Kabler, Heidi L, Sarap, Jennifer L, Beyer, Amanda R, Li, Pui-Kai, Selcer, Kyle W
• Format: Article
• Language: English
• Subjects: Animals; Arylsulfatases - metabolism; Biological and medical sciences; Cell Line; Cells, Cultured; Dehydroepiandrosterone Sulfate - metabolism; Estrone - analogs & derivatives; Estrone - biosynthesis; Estrone - metabolism; Female; Fundamental and applied biological sciences. Psychology; Granulosa cell; Granulosa Cells - enzymology; Granulosa Cells - metabolism; Hormone metabolism and regulation; In Vitro Techniques; Kinetics; Mammalian female genital system; Ovary; Ovary - enzymology; Ovary - metabolism; Rat; Rats; Rats, Sprague-Dawley; Steroid sulfatase; Steroidogenesis; Steroids - biosynthesis; Steryl-Sulfatase; Substrate Specificity; Vertebrates: reproduction
• ISSN: 0960-0760; 1879-1220
• DOI: 10.1016/S0960-0760(00)00171-0

Direct production of gonadal steroids from sulfated adrenal androgens may be an important alternative or complementary pathway for ovarian steroidogenesis. The conversion of sulfated adrenal androgens, present in serum at micromolar concentrations in adult women, into unconjugated androgens or estrogens requires steroid sulfatase (STS) activity. STS activity has not been characterized in the rat ovary. Substantial STS activity was present in homogenates of rat ovaries, primary cultures of rat granulosa cells, and a granulosa cell line, as determined by conversion of radiolabeled estrone sulfate (E 1S) to unconjugated estrone. The potent inhibitor estrone sulfamate eliminated the STS activity. Using E 1S as a substrate with microsomes prepared from a granulosa cell line, the K m of STS activity was approximately 72 μM, a value in agreement with previously published data for rat STS. Therefore, ovarian cells possess STS and can remove the sulfate from adrenal androgens such as dehydroepiandrosterone sulfate (DHEA-S). Using DHEA-S as a steroidogenic substrate represents an alternative model for the production of ovarian steroids versus the “two cell, two gonadotropin” model of ovarian estrogen synthesis, whereby thecal cells produce androgens from substrate cholesterol and granulosa cells convert the androgens into estrogens. The relative contribution of STS activity to ovarian steroidogenesis remains unclear but may have important physiological and pathophysiological implications.