Effect of central administration of prolactin-releasing peptide on feeding in chicks.
Prolactin-releasing peptide (PrRP) is one of the inhibitory factors in feeding regulation of mammals. However, no information is available for avian species. The present study was done to clarify the effect of intracerebroventricular (ICV) injection of PrRP on feeding in chicks. Firstly, we found that ICV injection of PrRP (94-1500 pmol) significantly increased food intake in chicks. The result was completely different from those obtained in mammals. The orexigenic effect of PrRP was significantly weaker than that of neuropeptide Y (NPY), a potent orexigenic peptide, on an equimolar basis. The orexigenic effect of NPY was further enhanced with coinjection of PrRP. These results suggest the existence of a novel orexigenic mechanism in the chick brain, which might differ from NPY-involved feeding regulatory pathway. In addition, ICV injection of PrRP significantly decreased the rectal temperature, but the effect was weaker than that of NPY, suggesting that PrRP may inhibit energy expenditure in chicks. Taken together, we showed here that PrRP may be involved in the regulation of both feeding behavior and energy metabolism in the chick brain.
Tachibana
Tetsuya
T
Laboratory of Advanced Animal and Marine Bioresources, Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka 812-8581, Japan. tetsu@brs.kyushu-u.ac.jp
Saito
Shin
S
Tomonaga
Shozo
S
Takagi
Tomo
T
Saito
Ei-Suke
ES
Nakanishi
Tomonori
T
Koutoku
Tomoyuki
T
Tsukada
Akira
A
Ohkubo
Takeshi
T
Boswell
Tim
T
Furuse
Mitsuhiro
M
D000818:Animals; D001069:Appetite Regulation / Q000502:physiology*; D001831:Body Temperature / Q000502:physiology; D002645:Chickens / Q000502:physiology*; D004435:Eating / Q000502:physiology*; D005247:Feeding Behavior / Q000502:physiology*; D007028:Hypothalamic Hormones / Q000008:administration & dosage / Q000502:physiology*; D007276:Injections, Intraventricular; D008297:Male; D009478:Neuropeptide Y / Q000502:physiology; D009479:Neuropeptides / Q000008:administration & dosage / Q000502:physiology*; D056690:Prolactin-Releasing Hormone
D007028:Hypothalamic Hormones; D009478:Neuropeptide Y; D009479:Neuropeptides; D056690:Prolactin-Releasing Hormone