In vivo effect of melatonin and gonadotropin-releasing hormone on testicular function in Rana temporaria.
Studies concerning pineal-gonadal interactions and investigations about the effect of the putative pineal hormone melatonin in male amphibians are very scarce. In this work we investigate the effects of melatonin, synthetic gonadotropin-releasing hormone (GnRH), or both when injected in Rana temporaria males. We conclude that melatonin inhibits spermiation and spermatogonial multiplication when injected alone or with GnRH. We have been unable to find any significant differences in plasma testosterone levels when melatonin or GnRH are injected alone, but when melatonin is injected with GnRH the levels of testosterone are significantly increased. These results seem to demonstrate that melatonin could play a role in the regulation of the gonadal function in the male Rana temporaria.
Alonso-Bedate
M
M
Departmento de Fisiologia Animal, Facultad de Biologia, Universidad Complutense de Madrid, Spain.
Delgado
M J
MJ
Carballada
R
R
D000818:Animals; D008297:Male; D008550:Melatonin / Q000494:pharmacology / Q000502:physiology*; D010906:Pituitary Hormone-Releasing Hormones / Q000494:pharmacology / Q000502:physiology*; D011896:Rana temporaria / Q000502:physiology*; D013094:Spermatozoa / Q000502:physiology; D013737:Testis / Q000378:metabolism / Q000502:physiology*; D013739:Testosterone / Q000378:metabolism
D010906:Pituitary Hormone-Releasing Hormones; D013739:Testosterone; D008550:Melatonin