In vivo pretreatment with human chorionic gonadotropin fails to reverse the dysfunction of isolated Leydig cells from chronically uremic rats.
In order to further investigate the previously reported hypogonadal state of chronically uremic rats, we examined the effects of in vivo pretreatment with human chorionic gonadotropin (hCG) on in vivo and in vitro Leydig cell function, comparing paired intact rats with rats made chronically uremic by 5/6 nephrectomy. The in vitro testosterone (T) secretory responses to varying concentrations of hCG or dibutyryl cAMP and the number of gonadotropin receptors were determined following hemicastration. The rats were then treated with hCG for 3 days and the remaining testes were removed and studied as before. Compared with intact rats, the uremic rats had higher serum concentrations of urea nitrogen (P less than 0.001); serum T concentrations were lower in uremic rats before (P less than 0.001), but not after (P greater than 0.6) treatment. Treatment produced increases in serum T only in uremic rats (P less than 0.001). Serum LH was lower in uremic rats before treatment (P less than 0.001) and was reduced (P less than 0.001) to similar levels (P greater than 0.8) in both groups after treatment. Baseline in vitro T secretion was lower (P less than 0.001) from Leydig cells of uremic than intact rats both before and after treatment. Analysis of variance of dose-response curves showed pre- and post-treatment T secretory responses to hCG or dibutyryl cAMP in vitro to be less from Leydig cells of uremic rats (P less than 0.01). Before treatment, Leydig cell gonadotropin receptor number was lower in uremic than intact rats (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D066298:In Vitro Techniques; D007676:Kidney Failure, Chronic / Q000097:blood / Q000503:physiopathology*; D007985:Leydig Cells / Q000187:drug effects / Q000502:physiology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000032:analysis; D011974:Receptors, LH; D013739:Testosterone / Q000097:blood / Q000378:metabolism; D014511:Uremia / Q000097:blood / Q000503:physiopathology*
D006063:Chorionic Gonadotropin; D011956:Receptors, Cell Surface; D011974:Receptors, LH; D013739:Testosterone; D003994:Bucladesine