Peripheral ghrelin selectively increases Fos expression in neuropeptide Y - synthesizing neurons in mouse hypothalamic arcuate nucleus.
Ghrelin, a peptide isolated from the rat stomach, is the endogenous ligand of the growth hormone-secretagogue receptor and also known to have orexigenic effect. We examined the influence of intraperitoneal (i.p.) injection of ghrelin on food intake and brain neuronal activity in freely fed mice. Ghrelin (3, 10 or 30 microg/mouse) dose-dependently increased food intake by 0.8-, 1.6- and 2.6-fold, respectively, at 30 min post injection. Ghrelin (10 microg/mouse) induces Fos expression selectively in the ventromedial part of the hypothalamic arcuate nucleus (Arc). No change in Fos expression was observed in other hypothalamic and hindbrain nuclei. About 90% of the Fos-positive neurons in the Arc expressed neuropeptide Y (NPY) messenger RNA. These data indicate that NPY neurons in the Arc are likely the primary target mediating i.p. ghrelin induced orexigenic effect.
Wang
Lixin
L
CURE: Digestive Diseases Research Center, VA Greater Los Angeles Healthcare System, Department of Medicine, University of California at Los Angeles, Building 115, Room 203, 11301 Wilshire Boulevard, Los Angeles, CA 90073, USA.
Saint-Pierre
David H
DH
Taché
Yvette
Y
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects; D054439:Ghrelin; D007274:Injections, Intraperitoneal; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009478:Neuropeptide Y / Q000096:biosynthesis* / Q000235:genetics; D036361:Peptide Hormones; D010455:Peptides / Q000008:administration & dosage* / Q000494:pharmacology; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D014018:Tissue Distribution
D054439:Ghrelin; D009478:Neuropeptide Y; D036361:Peptide Hormones; D010455:Peptides; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger