title: Effect of intraventricular injection of 5,6-dihydroxytryptamine on spermatogenesis and plasma testosterone levels in the rat.
abstract: Quantitative evaluation of spermatogenesis at stage VII of the cycle of the seminiferous epithelium and radioimmunoassay of plasma testosterone were performed in adult Wistar rats after intraventricular injection of 5,6-dihydroxytryptamine (5,6-DHT). The rats were killed 2, 10 and 21 days after injection. Brain 5-hydroxytryptamine (5-HT) and plasma testosterone levels were found to be significantly lower in all rats treated with 5,6-DHT. A significant reduction in step 7 spermatid count was also observed after 10 and 21 days. Supplementation with human chorionic gonadotrophin for 21 days in rats injected with 5,6-DHT partially prevented the step 7 spermatid degeneration and increased testosterone levels without producing any effect on brain concentrations of 5-HT. These results suggest that changes in testicular steroidogenesis and spermatogenesis are secondary to pituitary gonadotrophin release which, in turn, is under the influence of brain 5-HT neurones.
mesh_terms: D015115:5,6-Dihydroxytryptamine / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001923:Brain Chemistry; D002452:Cell Count; D007276:Injections, Intraventricular; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012670:Seminiferous Epithelium / Q000187:drug effects; D012701:Serotonin / Q000032:analysis; D013087:Spermatids / Q000187:drug effects; D013091:Spermatogenesis / Q000187:drug effects*; D013739:Testosterone / Q000097:blood*; D013997:Time Factors
chemical_list: D012701:Serotonin; D013739:Testosterone; D015115:5,6-Dihydroxytryptamine