Spermatogenesis in rat: effect of L-tryptophan loading.
The present experiment was designed to assess the role of enhanced central 5-HT level on testicular steroidogenesis and spermatogenesis of rat. L-tryptophan, a precursor in the synthesis of 5-HT in brain, was injected in male rats on a short-term (7-days) and a long-term (21-days) basis. The short-term treatment had no effect on the spermatogenic pattern (Stage - VII of the cycle of the seminiferous epithelium), while the long-term treatment showed a degenerative change (reduced count of the germ cells). Both modes of treatment reduced the activity of testicular delta 5-3 beta-HSD without affecting NADH2-linked Diaphorase activity. Histological study of the Leydig cells' nuclear area also revealed a marked reduction after both the modes of treatment. Human chorionic gonadotropin supplementation in the long-term treatment restored the spermatogenesis, delta 5-3 beta-HSD activity and Leydig cells' nuclear area towards the vehicle treated control. The inhibition of spermatogenesis and steroidogenesis reflects a decrease in the pituitary gonadotropin release under the influence of enhanced 5-HT synthesis in brain, after L-tryptophan loading.
D015096:3-Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors; D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D005837:Genitalia, Male / Q000033:anatomy & histology; D007985:Leydig Cells / Q000648:ultrastructure; D008297:Male; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013076:Sperm Count; D013087:Spermatids / Q000187:drug effects; D013091:Spermatogenesis / Q000187:drug effects*; D014364:Tryptophan / Q000494:pharmacology*
D006063:Chorionic Gonadotropin; D014364:Tryptophan; D015096:3-Hydroxysteroid Dehydrogenases