Assessment of the contribution of Leydig cells to the secretion of inhibin by the rat testis.
Cultured Leydig cells secreted 1.3-4.3 ng 1-26 alpha-inhibin/10(6) cells/24 h, and although this was unaffected by human chorionic gonadotrophin (hCG), these cells could contribute to the intratesticular and blood levels of inhibin. The present study evaluated this contribution in rats in which the Leydig cells were destroyed by injection of ethane dimethane sulphonate (EDS). In these animals, inhibin levels increased in testicular interstitial fluid (IF), and in testicular (TV) and spermatic (SV) venous blood. In EDS-treated rats supplemented for 21 days with 1 or 25 mg testosterone esters to maintain full spermatogenesis and/or suppress the elevated follicle-stimulating hormone (FSH) levels and prevent Leydig cell regeneration, significant changes occurred in the levels of inhibin in IF, in TV and SV plasma and in the route of secretion of inhibin from the testis (i.e. via IF or seminiferous tubule fluid). However, none of these changes was related to the presence or absence of Leydig cells. It is concluded that Leydig cells make little contribution to the intratesticular and blood levels of inhibin in the adult rat.
Maddocks
S
S
MRC Reproductive Biology Unit, Centre for Reproductive Biology, Edinburgh, Scotland, U.K.
Sharpe
R M
RM
D000818:Animals; D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D005110:Extracellular Space / Q000032:analysis; D007265:Inhibins / Q000097:blood / Q000378:metabolism*; D007985:Leydig Cells / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013737:Testis / Q000098:blood supply / Q000166:cytology / Q000378:metabolism*
D006063:Chorionic Gonadotropin; D007265:Inhibins