LH contamination may explain FSH effects on rat Leydig cells

Publisher Website
Google Scholar
Abstract
Treatment of immature, hypophysectomized male rats with 50 .mu.g ovine FSH [follicle stimulating hormone] (NIH-FSH-S12) twice a day for 5 days stimulated the maximum quantity of 17.beta.-hydroxyandrogen produced by isolated Leydig cells in response to hCG [human chorionic gonadotropin]. Pretreatment of the FSH preparation with an LH [luteinizing hormone] antiserum in 1 study markedly reduced and in another study completely abolished this stimulatory effect of FSH, but only slightly impaired the capacity of the hormone to stimulate the Sertoli cell in vivo (epididymal androgen-binding protein). Administration of another highly potent FSH preparation (LER-1881) had no discernible effects on the dose-response characteristics of the Leydig cells but was superior to the NIH-FSH-S12 in its capacity for stimulating the Sertoli cell. When all hormone preparations were tested for their ability to stimulate steroid secretion from normal Leydig cells in vitro, a close correlation was obtained between their Leydig cell-stimulating activity (a measure of LH contamination) and their capacity to alter Leydig cell responsiveness after in-vivo treatment. FSH treatment had no effects on specific LH binding per 106 Leydig cells. The stimulatory influence of FSH on rat Leydig cells may to some extent be a result of the LH contaminating the hormone preparation.