Gonadotropin-releasing hormone 2 suppresses food intake in the zebrafish, Danio rerio.
Gonadotropin-releasing hormone 2 suppresses food intake in the zebrafish, Danio rerio.
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DOI：
10.3389/fendo.2012.00122
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发表时间：
2012
影响因子：
5.2
通讯作者：
Matsuda K
中科院分区：
文献类型：
--
作者：
Nishiguchi R;Azuma M;Yokobori E;Uchiyama M;Matsuda K
促性腺激素释放激素（GnRH）是一种进化上保守的神经肽，具有10个氨基酸残基，其中存在几种结构变体。一种被称为GnRH 2（[His 5 Trp 7 Tyr 8]GnRH，也称为鸡GnRH II）的分子形式广泛分布于除啮齿动物外的脊椎动物中，最近被认为与金鱼摄食行为的调节有关。然而，GnRH 2对其他鱼类摄食行为的影响尚未研究。因此，在本研究中，我们研究了GnRH 2在斑马鱼模型中调节进食行为的作用，并检查了其在脑室内（ICV）给药后对食物摄入的参与。ICV注射GnRH 2在0.1和1 pmol/g体重（BW）诱导的摄食量显着减少，在30分钟喂养后的剂量依赖性的方式。在给药后30分钟观察期内，ICV注射1 pmol/g BW的GnRH 2显著降低了累积摄食量。通过以25 pmol/g BW的GnRH I型受体拮抗剂Antide处理，GnRH 2的促性腺激素作用被完全阻断。我们还研究了喂养条件对下丘脑中GnRH 2转录物表达水平的影响。从提供过量食物7天的鱼中获得的GnRH 2 mRNA水平高于正常喂养的鱼。这些结果表明，在斑马鱼中，GnRH 2作为一种促性腺激素因子，就像金鱼中的情况一样。
Gonadotropin-releasing hormone (GnRH) is an evolutionarily conserved neuropeptide with 10 amino acid residues, of which several structural variants exist. A molecular form known as GnRH2 ([His5 Trp7 Tyr8]GnRH, also known as chicken GnRH II) is widely distributed in vertebrates except for rodents, and has recently been implicated in the regulation of feeding behavior in goldfish. However, the influence of GnRH2 on feeding behavior in other fish has not yet been studied. In the present study, therefore, we investigated the role of GnRH2 in the regulation of feeding behavior in a zebrafish model, and examined its involvement in food intake after intracerebroventricular (ICV) administration. ICV injection of GnRH2 at 0.1 and 1 pmol/g body weight (BW) induced a marked decrease of food consumption in a dose-dependent manner during 30 min after feeding. Cumulative food intake was significantly decreased by ICV injection of GnRH2 at 1 pmol/g BW during the 30-min post-treatment observation period. The anorexigenic action of GnRH2 was completely blocked by treatment with the GnRH type I receptor antagonist Antide at 25 pmol/g BW. We also examined the effect of feeding condition on the expression level of the GnRH2 transcript in the hypothalamus. Levels of GnRH2 mRNA obtained from fish that had been provided excess food for 7 days were higher than those in fish that had been fed normally. These results suggest that, in zebrafish, GnRH2 acts as an anorexigenic factor, as is the case in goldfish.