Serum leptin levels after central and systemic injection of a serotonin precursor, 5-hydroxytryptophan, in mice

• Published in: European journal of pharmacology Vol. 406; no. 1; pp. 159 - 162
• Main Authors: Yamada, Jun, Ujikawa, Masanori, Sugimoto, Yumi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 06.10.2000; Elsevier
• Subjects: 5-HT (5-hydroxytryptamine, serotonin); 5-HTP (5-Hydroxytryptophan); 5-Hydroxytryptophan - pharmacology; Animals; Benserazide; Benserazide - pharmacology; Biological and medical sciences; Dose-Response Relationship, Drug; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; Injections, Intraperitoneal; Injections, Intraventricular; Leptin; Leptin - blood; Male; Mice; Mouse; Serotonin - pharmacology; Serotonin Agents - pharmacology; Time Factors; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Benserazide; 5-HTP (5-Hydroxytryptophan); 5-HT (5-hydroxytryptamine, serotonin); Mouse; Leptin; Feeding behavior; Serotonin; Rodentia; Neuromodulation; Precursor; Blood; Vertebrata; Mammalia; Food intake; Animal; Intracerebral administration; Neurotransmitter; Release
• ISSN: 0014-2999; 1879-0712
• DOI: 10.1016/S0014-2999(00)00624-5

Effects of peripheral and central injections of a serotonin (5-hydroxytryptamine, 5-HT) precursor, 5-hydroxytryptophan (5-HTP), on serum leptin levels were studied in mice. Intracerebroventricular (i.c.v.) injection of 5-HTP or 5-HT did not increase serum leptin levels, although the peripheral injection of 5-HTP elicited an apparent hyperleptinemia. The elevation of serum leptin levels in mice induced by the peripheral injection of 5-HTP was inhibited by pretreatment with the peripheral aromatic amino acid decarboxylase inhibitor, benserazide. Furthermore, the peripheral injection of 5-HT increased serum leptin levels. These results suggest that the hyperleptinemia following systemic injection of 5-HTP is elicited by 5-HT formed in the peripheral system.