TY - JOUR
T1 - The orexigenic effect of GnIH is mediated by central opioid receptors in chicks
AU - Tachibana, Tetsuya
AU - Masuda, Naoto
AU - Tsutsui, Kazuyoshi
AU - Ukena, Kazuyoshi
AU - Ueda, Hiroshi
PY - 2008/5
Y1 - 2008/5
N2 - Gonadotropin-inhibiting hormone (GnIH) is a newly discovered hypothalamic hormone which suppresses gonadotropin synthesis and release from the anterior pituitary. Recently, we found that intracerebroventricular (ICV) injection of GnIH stimulated feeding behavior of chicks (Gallus gallus) and suggested that GnIH is one of orexigenic peptides. However, the mechanism underlying the orexigenic effect is still unknown. In the present study, we examined whether the orexigenic effect of GnIH is related to opioid and nitric oxide (NO) systems. The orexigenic effect of ICV-injected GnIH was attenuated by co-injection of beta-funaltrexamine (an opioid mu-receptor antagonist) but not ICI-174,864 and nor-binaltorphimine (antagonists of opioid delta- and kappa-receptors, respectively). The co-injection of non-selective NO synthase inhibitor did not affect GnIH-induced feeding behavior. The present study demonstrated that the GnIH-induced feeding might be mediated by opioid mu-receptor in chicks.
AB - Gonadotropin-inhibiting hormone (GnIH) is a newly discovered hypothalamic hormone which suppresses gonadotropin synthesis and release from the anterior pituitary. Recently, we found that intracerebroventricular (ICV) injection of GnIH stimulated feeding behavior of chicks (Gallus gallus) and suggested that GnIH is one of orexigenic peptides. However, the mechanism underlying the orexigenic effect is still unknown. In the present study, we examined whether the orexigenic effect of GnIH is related to opioid and nitric oxide (NO) systems. The orexigenic effect of ICV-injected GnIH was attenuated by co-injection of beta-funaltrexamine (an opioid mu-receptor antagonist) but not ICI-174,864 and nor-binaltorphimine (antagonists of opioid delta- and kappa-receptors, respectively). The co-injection of non-selective NO synthase inhibitor did not affect GnIH-induced feeding behavior. The present study demonstrated that the GnIH-induced feeding might be mediated by opioid mu-receptor in chicks.
KW - Chicks
KW - Feeding
KW - Gonadotropin-inhibiting hormone
KW - Intracerebroventricular injection
KW - Opioid
UR - http://www.scopus.com/inward/record.url?scp=42749089618&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=42749089618&partnerID=8YFLogxK
U2 - 10.1016/j.cbpa.2008.02.018
DO - 10.1016/j.cbpa.2008.02.018
M3 - Article
C2 - 18378171
AN - SCOPUS:42749089618
VL - 150
SP - 21
EP - 25
JO - Comparative Biochemistry & Physiology; A: Comparative Physiology
JF - Comparative Biochemistry & Physiology; A: Comparative Physiology
SN - 1095-6433
IS - 1
ER -