Gonadotropin-releasing hormone II (GnRH II) mediates the anorexigenic actions of α-melanocyte-stimulating hormone (α-MSH) and corticotropin-releasing hormone (CRH) in goldfish

详细信息    查看全文

• 作者：Ki Sung Kang¹ ; ^a ; Kanako Shimizu¹ ; ^a ; Morio Azuma^a ; Yuhta Ui^a ; Kouta Nakamura^a ; Minoru Uchiyama^a ; Kouhei Matsuda ; ^a ; ^{kmatsuda@sci.u-toyama.ac.jp}
• 关键词：Goldfish ; GnRH II ; Anorexigenic action ; MC4R ; MT II ; CRH receptor ; GnRH receptor ; Antide
• 刊名：Peptides
• 出版年：2011
• 出版时间：January 2011
• 年：2011
• 卷：32
• 期：1
• 页码：31-35
• 全文大小：244 K

文摘

Intracerebroventricular (ICV) administration of gonadotropin-releasing hormone II (GnRH II), which plays a crucial role in the regulation of reproduction in vertebrates, markedly reduces food intake in goldfish. However, the neurochemical pathways involved in the anorexigenic action of GnRH II and its interaction with other neuropeptides have not yet been identified. Alpha-melanocyte-stimulating hormone (α-MSH), corticotropin-releasing hormone (CRH) and CRH-related peptides play a major role in feeding control as potent anorexigenic neuropeptides in goldfish. However, our previous study has indicated that the GnRH II-induced anorexigenic action is not blocked by treatment with melanocortin 4 receptor (MC4R) and CRH receptor antagonists. Therefore, in the present study, we further examined whether the anorexigenic effects of α-MSH and CRH in goldfish could be mediated through the GnRH receptor neuronal pathway. ICV injection of the MC4R agonist, melanotan II (80 pmol/g body weight; BW), significantly reduced food intake, and its anorexigenic effect was suppressed by ICV pre-administration of the GnRH type I receptor antagonist, antide (100 pmol/g BW). The CRH-induced (50 pmol/g BW) anorexigenic action was also blocked by treatment with antide. ICV injection of CRH (50 pmol/g BW) induced a significant increase of the GnRH II mRNA level in the hypothalamus, while ICV injection of melanotan II (80 pmol/g BW) had no effect on the level of GnRH II mRNA. These results indicate that, in goldfish, the anorexigenic actions of α-MSH and CRH are mediated through the GnRH type I receptor-signaling pathway, and that the GnRH II system regulates feeding behavior.