Brain hormones and appetite in fish

1.黑色素浓缩激素（MCH）的barfin比目鱼是由17个残基，这不同于鲑鱼MCH的位置2。合成的MCH的生物活性通过腹腔注射肽后黑素体在比目鱼皮肤中的聚集来证明。MCH mRNA的拷贝数是更大的鱼饲养的白色背景比那些饲养的黑色背景。MCH基因在禁食组的表达水平高于对照组，表明MCH与摄食量有关.我们克隆了两个MCH受体（MCH-R）从barfin比目鱼。MCH-R1的表达仅限于脑，而MCH-R2的转录本在包括脑在内的几种组织中检测到。在黑色背景下饲养的鱼眼侧皮肤中MCH-R2的表达高于在白色背景下饲养的鱼.在金鱼，累积摄食量减少脑室内注射MCH，而增加脑室内注射MCH抗血清。禁食金鱼下丘脑部分区域MCH免疫反应阳性胞体的数量明显减少。这些结果表明，MCH具有作为金鱼促氧化神经肽的潜力.我们克隆了三个POMC亚型从barfin比目鱼。POMC-A的表达仅限于垂体，而POMC-B和POMC-C的转录本在包括垂体在内的几种组织中检测到。在长鳍拟庸鲽脑垂体的远侧部和中间部，POMC的翻译后加工各不相同.黑素皮质素1和4受体的表达，观察在大脑，眼球，睾丸，和皮肤的barfin比目鱼。黑皮质素4受体也在肝脏中表达，其表达随着禁食而增加。结果表明，该受体与能量稳态的关联。

1. Melanin-concentrating hormone (MCH) of the barfin flounder is composed of 17 residues, which differs from salmon MCH at a position 2. The biological activity of synthetic MCH was demonstrated by the aggregation of melanosomes in flounder skin after intraperitoneal injection of the peptide. The number of MCH mRNA copies was greater in fish reared with a white background than in those reared with a black background. The MCH gene expression level in the brain was higher in fasted fish than in controls, indicating the association of MCH with food intake.2. We cloned two MCH receptors (MCH-R) from the barfin flounder. The expression of MCH-R1 was confined to the brain, while transcripts of MCH-R2 were detected in several tissues including the brain. The expression of MCH-R2 in eyed-sideskin was higher in fish reared with a black background than with a white background.3. In goldfish, cumulative food intake was decreased by intracerebroventricular injection of MCH, while it was increased by intracerebroventricular injection of MCH antiserum. The number of MCH immunoreactive somata in a part of the goldfish hypothalamus decreased significantly in fasted fish as compared with fed fish. These results indicate that MCH has a potential to function as an anorexigenic neuropeptide in goldfish.4. We cloned three POMC subtypes from the barfin flounder. The expression of POMC-A was confined to the pituitary, while transcripts of POMC-B and-C were detected in several tissues including the pituitary. Posttranslational processing of POMC of the pars distalis and pars intermedia in the barfin flounder pituitary differs from each other.5. Expressions of melanocortin 1 and 4 receptors were observed in the brain, eye-balls, testes, and skin of the barfin flounder. Melanocortin 4 receptor was also expressed in the liver, of which expression was increased by fasting. The results suggest the association of this receptor with energy homeostasis.