Failure of N-(2,4-dinitrophenyl)-5-methoxytryptamine (a putative melatonin antagonist) and of N-(3,5-dinitrophenyl)-5-methoxytryptamine to prevent the effects of injections of melatonin in the late afternoon on testicular activity of the golden hamster.
Daily injections of 10 micrograms melatonin in the late afternoon into male golden hamsters kept under a long photoperiod (14 h light: 10 h darkness) and at low ambient temperature 6 +/- 1 degrees C) induced a complete gonadal atrophy after 4 weeks. When administered under the same conditions at doses of 25 micrograms, neither N-(3,5-dinitrophenyl)-5-methoxytryptamine or N-(2,4-dinitrophenyl)-5-methoxytryptamine, a putative melatonin antagonist termed ML-23 in the literature, showed any effect on testicular activity. Moreover, these two drugs were also unable to prevent melatonin-induced gonadal atrophy when injected 30 min before melatonin. The results demonstrate that in the golden hamster and in the present experimental conditions, these drugs do not have the melatonin-antagonistic properties as described in the rat.
Pévet
P
P
URA-CNRS 1332 Neurobiologie des fonctions rythmiques et saisonnières, Laboratoire de Zoologie, Université Louis Pasteur, Strasbourg, France.
Masson-Pévet
M
M
Chantegrel
J
J
Marsura
A
A
Luu-Duc
C
C
Claustrat
B
B
D008735:5-Methoxytryptamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001284:Atrophy / Q000139:chemically induced; D003080:Cold Temperature; D006224:Cricetinae; D008027:Light; D008297:Male; D008550:Melatonin / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D008647:Mesocricetus; D012701:Serotonin / Q000031:analogs & derivatives*; D013737:Testis / Q000187:drug effects* / Q000473:pathology
C053008:ML 23; C059440:N-(2,4-dinitrophenyl)-5-methoxytryptamine; D012701:Serotonin; D008735:5-Methoxytryptamine; D008550:Melatonin