Abstract
Ovarian tissue from a 38 year old woman was incubated with and without FSH-(follicle-stimulating hormone) and LH-preparations (luteinizing hormone) from human pituitary glands. Both preparations stimulated the conversion of labelled androstenedione to estrone and 17[beta]-estradiol. In both cases this effect was blocked by addition to the incubation medium of serum from rabbits immunized against HCG (human chorionic gonadotropln).