Intracerebroventricular injection of ghrelin and growth hormone releasing factor inhibits food intake in neonatal chicks.
Growth hormone releasing factor (GRF) is known to stimulate feeding of rats. Ghrelin, a novel growth hormone (GH)-releasing acylated peptide, was recently isolated from rat stomach. It also stimulates the release of GH from the anterior pituitary through the GH secretagogue receptor (GHS-R) and feeding in the rat. We have investigated the effects of ghrelin and GRF on food intake of the neonatal chick. In Experiment 1, 0, 1.25, 2.5 and 5 microg of ghrelin were administered intracerebroventricularly (i.c.v.) to ad libitum fed birds. In Experiment 2, the effect of (i.c.v.) injection of 0, 1.25, 2.5 and 5 microg of GRF was investigated. Both peptides strongly inhibited food intake of the chick during the 2-h post-injection period. In the third experiment, 0, 0.5, 1 and 2 microg of ghrelin was injected i.c.v. in chicks previously deprived of food for 3 h. Food intake was again inhibited by ghrelin in a dose-dependent manner. These results suggest that the mechanisms for feeding of the neonatal chick through GH release are different from mammals.
Furuse
M
M
Laboratory of Advanced Animal and Marine Bioresources, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 812-8581, Fukuoka, Japan. furuse@agr.kyushu-u.ac.jp
Tachibana
T
T
Ohgushi
A
A
Ando
R
R
Yoshimatsu
T
T
Denbow
D M
DM
D000367:Age Factors; D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D004435:Eating / Q000187:drug effects*; D054439:Ghrelin; D013007:Growth Hormone-Releasing Hormone / Q000737:chemistry / Q000494:pharmacology*; D007276:Injections, Intraventricular; D008297:Male; D008969:Molecular Sequence Data; D036361:Peptide Hormones; D010455:Peptides / Q000494:pharmacology*; D010903:Pituitary Gland, Anterior / Q000502:physiology
D054439:Ghrelin; D036361:Peptide Hormones; D010455:Peptides; D013007:Growth Hormone-Releasing Hormone