Steroid Biosynthesis by Isolated Human Ovarian Follicular Cells in Vitro*

Abstract

Cultured thecal preparations from human ovarianfollicles obtained from patients during the follicular phase ofthe menstrual cycle produced large amounts of Δ⁴-androstenedioneand smaller amounts of testosterone and other androgenswhen stimulated by hCG, (Bu)₂cAMP, and prostaglandin E₂, butnot when stimulated by FSH. Prostaglandin E₂ also stimulatedthecal cAMP production under the same conditions. By contrast,androgen production by granulosa cells was negligible with orwithout gonadotropins in the culture medium. Granulosa cellsalso did not produce 17β-estradiol, even when exposed to FSHand hCG, unless supplied with exogenous Δ⁴-androstenedione.On the other hand, thecal preparations did not produce significantamounts of 17β-estradiol even in the presence of FSH, hCG,and relatively large amounts of exogenous Δ⁴-androstenedione.These observations suggest that Δ⁴-androstenedione producedby LH or hCG-stimulated thecal cells is the main substrate forthe synthesis of 17β-estradiol by FSH-stimulated granulosa cellsin vivo. (J. Clin Endocrinol Metab51: 1407, 1980)