Identification of novel ghrelin receptor in fish and clarification of the relationship between the receptor and biological action.

在本研究中，我们克隆了四种功能性Ghrelin受体(GHS-R1a-1、1a-2、2a-1和2a-2)的cDNA，它们分别由360、360、366和367个氨基酸组成。每种受体的mRNA都表现出组织特异性表达，这表明每种受体在金鱼体内都介导了Ghrelin的组织特异性作用。Ghrelin受体的一种，GHS-R1a，迄今已被发现存在于除鱼类以外的脊椎动物中。我们试图从金鱼大脑和肠道的组织提取物中分离出新的功能GHS-Ra的新配体，但不幸的是，在本研究过程中，新的配体未能找到。

In this study, we cloned cDNAs for four functional ghrelin receptors (GHS-R1a-1, 1a-2, 2a-1 and 2a-2) that composed of 360, 360, 366 and 367 amino acids, respectively in goldfish brain. Each receptor mRNA showed tissue-specific expression, suggesting that each receptor mediates tissue-specific action of ghrelin in goldfish. One species of ghrelin receptor, GHS-R1a has been known to be present in vertebrates other than fish examined so far. We tried to isolate new ligands for the new functional GHS-Ra, which is the novel type of ghrelin receptor, from tissue extracts of goldfish brain and intestine, but unfortunately the new ligand was not able to find out during the course of this study.