Testicular Control of Follicle-Stimulating Hormone Secretion

The role of testicular fluid on blood plasma levels of FSH and LH in the ram (1)

“…Ovine testicular fluid secreted by the testis into the epididymis has been shown to contain inhibin (Setchell and Sirinathsinghji, 1972 ;Setchell and Jacks, 1974 ;Baker et al, 1976 ;Blanc and Dacheux, 1976 ;Davies et al, 1976 ;Franchimont et al, 1977). Since this substance is known to regulate FSH and LH in the ram (Blanc et al, 1978 ;Cahoreau et al, 1979), we were interested to know whether the RTF has a regulatory role on the level of gonadotrophins in the peripheral blood of the adult ram, or whether, since testicular lymph is known to contain inhibin activity (Eddie et al, 1977 ;Baker et al, 1978), this role might be relevant to the inhibin secreted by the Sertoli cells into the extratubular compartment of the testis and drained through the lymphatic vessels to the blood stream.…”

Testosterone feedback on FSH secretion in male sheep

“…Feedback on LH, for example, is thought to be mediated exclusively by gonadal steroids (Crim & Geschwind, 1972; Schanbacher & Ford, 1977;Parrott & Davies, 1979). FSH secretion, on the other hand, is influenced by both gonadal steroids (Schanbacher & Ford, 1977;Parrott & Davies, 1979;Schanbacher, 1979;1980) and a non-steroidal factor referred to as inhibin (Setchell & Jacks, 1974;Baker et al, 1976;Blanc & Dacheux, 1976;Keogh et al, 1976). The specific increase in FSH in rams after hemicastration provides the classical type of evidence for the existence of inhibin (Walton, Evins & Waites, 1978;Walton, E vins, Hillard & Waites, 1980 Schanbacher (1980).…”

Relationship Between Hormone Levels and Testicular Biopsies of Azoospermic Men

“…All hypogonadal men had plasma T levels under 2 ng/mL. In fact, T levels below 3 ng/mL confirm the clinical diagnosis of hypogonadism [2].…”

“…The increase in FSH is associated with germinal cell damage [7,10]. Elevation of FSH is presumably related to decreased inhibin production by the Sertoli cells (SC) [2,5]. Physical examination and, above all, testicular volume and serum FSH are certainly crucial in the management of azoospermic men; however, these findings are not totally informative since it is mandatory to know the microscopic structure of the testicular tissue [6].…”