title: Central and peripheral des-acyl ghrelin regulates body temperature in rats.
abstract: In the present study using rats, we demonstrated that central and peripheral administration of des-acyl ghrelin induced a decrease in the surface temperature of the back, and an increase in the surface temperature of the tail, although the effect of peripheral administration was less marked than that of central administration. Furthermore, these effects of centrally administered des-acyl ghrelin could not be prevented by pretreatment with [D-Lys3]-GHRP-6 GH secretagogue receptor 1a (GHS-R1a) antagonists. Moreover, these actions of des-acyl ghrelin on body temperature were inhibited by the parasympathetic nerve blocker methylscopolamine but not by the sympathetic nerve blocker timolol. Using immunohistochemistry, we confirmed that des-acyl ghrelin induced an increase of cFos expression in the median preoptic nucleus (MnPO). Additionally, we found that des-acyl ghrelin dilated the aorta and tail artery in vitro. These results indicate that centrally administered des-acyl ghrelin regulates body temperature via the parasympathetic nervous system by activating neurons in the MnPO through interactions with a specific receptor distinct from the GHS-R1a, and that peripherally administered des-acyl ghrelin acts on the central nervous system by passing through the blood-brain barrier, whereas it exerts a direct action on the peripheral vascular system.
authors.affiliation: Department of Veterinary Physiology, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Inoue
authors.forename: Keiko
authors.initials: K
authors.lastname: Nakahara
authors.forename: Keisuke
authors.initials: K
authors.lastname: Maruyama
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Kenji
authors.initials: K
authors.lastname: Kangawa
authors.forename: Noboru
authors.initials: N
authors.lastname: Murakami
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects; D001158:Arteries / Q000187:drug effects; D001340:Autonomic Nerve Block; D001831:Body Temperature / Q000187:drug effects*; D002490:Central Nervous System / Q000378:metabolism*; D004333:Drug Administration Routes; D054439:Ghrelin / Q000008:administration & dosage*; D008297:Male; D019832:N-Methylscopolamine / Q000008:administration & dosage; D010276:Parasympatholytics / Q000008:administration & dosage; D017933:Peripheral Nervous System / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014664:Vasodilation
chemical_list: D054439:Ghrelin; D010276:Parasympatholytics; C422650:ghrelin, des-n-octanoyl; D019832:N-Methylscopolamine