Effect of a synthetic pineal tetrapeptide (Ala-Glu-Asp-GLy) on melatonin secretion by the pineal gland of young and old rats.
The pineal gland contains many peptides known to be implicated in melatonin production. We examined the effects of a synthetic pineal tetrapeptide Ala-Glu-Asp-Gly on melatonin secretion by the pineal gland. The tetrapeptide effects on pineal gland melatonin secretion were studied in young (9 weeks) and old (27 months) male Wistar rats using a perifusion device. Pineal tetrapeptide at the concentrations used (10(-4) to 10(-6) M) had no significant effect upon melatonin secretion whatever the age of the animals, young or old. We also looked at the effect of the tetrapeptide on pineal melatonin stimulated by a beta-adrenergic agonist, isoproterenol. We found that isoproterenol-induced melatonin increase was not modified by the tetrapeptide. Our results suggest that the pineal tetrapeptide Ala-Glu-Asp-Gly, does not seem to play a role, at least in vitro, in the control of melatonin secretion by the rat pineal gland.
Djeridane
Y
Y
Faculty of Medicine Pitié-Salpêtrière, Medical Biochemistry and Molecular Biology, Paris, France.
Khavinson
V Kh
VKh
Anisimov
V N
VN
Touitou
Y
Y
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000375:Aging / Q000378:metabolism*; D000818:Animals; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008550:Melatonin / Q000378:metabolism*; D009842:Oligopeptides / Q000494:pharmacology*; D009994:Osmolar Concentration; D010870:Pineal Gland / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D000318:Adrenergic beta-Agonists; D009842:Oligopeptides; D008550:Melatonin; D007545:Isoproterenol; C421253:alanyl-glutamyl-aspartyl-glycine