E Itoh1, M Fujimiya, A Inui. 1. Pharmaceutical Research Department, Ube Research Lab, Japan.
Abstract
BACKGROUND: Whether or not peptide YY (PYY)-induced hyperphagia is modified by the histaminergic system in the brain is not yet known. METHODS: We investigated the effect on feeding of intracerebroventricular (ICV) administration of a specific histamine H3 receptor antagonist prior to ICV administration of PYY in rats. RESULTS: PYY (1, 3, and 10 micrograms/10 microL) strongly induced feeding behavior in a dose-dependent manner in sated rats. The 4-hour food intake induced by 3 micrograms/10 microL of PYY was equal to that induced by a 16-hour fast. The ICV administration of thioperamide (40.8, 122.4, and 408.5 micrograms/10 microL) did not suppress the 4-hour food intake induced by 16-hour fasting; however, thioperamide produced dose-dependent and strong inhibition of hyperphagia induced by a 3-microgram dose of PYY. CONCLUSIONS: These results suggest that the effect of PYY on appetite is different than that induced by fasting and may involve a histaminergic mechanism.
BACKGROUND: Whether or not peptide YY (PYY)-induced hyperphagia is modified by the histaminergic system in the brain is not yet known. METHODS: We investigated the effect on feeding of intracerebroventricular (ICV) administration of a specific histamine H3 receptor antagonist prior to ICV administration of PYY in rats. RESULTS:PYY (1, 3, and 10 micrograms/10 microL) strongly induced feeding behavior in a dose-dependent manner in sated rats. The 4-hour food intake induced by 3 micrograms/10 microL of PYY was equal to that induced by a 16-hour fast. The ICV administration of thioperamide (40.8, 122.4, and 408.5 micrograms/10 microL) did not suppress the 4-hour food intake induced by 16-hour fasting; however, thioperamide produced dose-dependent and strong inhibition of hyperphagia induced by a 3-microgram dose of PYY. CONCLUSIONS: These results suggest that the effect of PYY on appetite is different than that induced by fasting and may involve a histaminergic mechanism.
Authors: Ryo Yoshimoto; Yasuhisa Miyamoto; Ken Shimamura; Akane Ishihara; Kazuhiko Takahashi; Hidehito Kotani; Airu S Chen; Howard Y Chen; Douglas J Macneil; Akio Kanatani; Shigeru Tokita Journal: Proc Natl Acad Sci U S A Date: 2006-09-05 Impact factor: 11.205
Authors: A J Barbier; C Berridge; C Dugovic; A D Laposky; S J Wilson; J Boggs; L Aluisio; B Lord; C Mazur; C M Pudiak; X Langlois; W Xiao; R Apodaca; N I Carruthers; T W Lovenberg Journal: Br J Pharmacol Date: 2004-10-04 Impact factor: 8.739