GnRH及其受体在2种真骨鱼消化系统中存在的免疫细胞化学证据

An immunocytochemical evidence for the presence of GnRH and GnRHR in the digestive system of two teleosts

用链霉亲和素-生物素化过氧化物酶复合物(streptavidinbiotin peroxidasecomplex,SABC)免疫细胞化学方法,使用促性腺激素释放激素(gonadotropin releasinghormone,GnRH),促性腺激素释放激素受体(gonadotropin releasinghormonereceptor,GnRHR)2种抗血清对黄颡鱼(Pelteobagrusfulvidraco)和鲇(Silurusasotus)的食道、贲门、胃底、幽门、前肠、中肠、后肠和胰中的免疫活性内分泌细胞进行了定位。结果表明:在鲇的食道、胃、肠、肠固有膜、肠肌间神经丛、胰腺和胰岛中均存在着GnRH和GnRHR免疫活性阳性反应;黄颡鱼消化系统中除了在食道和胰岛中未见GnRH和GnRHR的免疫活性阳性反应外,其他部位均有阳性反应,而且GnRH和GnRHR分泌细胞的分布模式相类似。说明胃肠道中GnRH分泌细胞可能以自分泌或旁分泌方式参与消化功能的调节。本研究首次证实在鱼类的消化系统中存在着GnRH及其受体的免疫活性内分泌细胞,可为GnRH功能的多样性等研究领域提供新的形态学依据。

By using the strept avidin biotin-peroxidase complex(SABC) immunocytochemical staining technique, the immunoreactive endocrine cells in the esophagus, cardia, fundus ventriculi, pylorus, foregut, midgut, hindgut, pancreas and liver of oriental sheatfish(Silurus asotus) and yellow catfish(Pelteobagrus fulvidraco) were localized with 2 kinds of antisera-gonadotropin releasing hormone(GnRH) and gonadotropin releasing hormone receptor(GnRHR). The result showed that there was GnRH and GnRHR immunoreactive positive reaction in the esophagus, stomach, intestinum, membrana propria, nerve plexus in myenteron, pancreas and pancreatic island of S. asotus and in the digestive system of P. fulvidraco, and the immunoreactive positive reaction of GnRH and GnRHR was also found in all parts except in the esophagus and pancreatic island, and the distributive patterns of GnRH and GnRHR are similar. It is suggested that the GnRH in the gastrointestinal tract may participate in modulation the digestive function via autocrine or paracrine mechanism. It is demonstrated for the first time that there are GnRH and GnRHR immunoreactive endocrine cells in the digestive system of fishes. It provided new morphological basis for the research field of the functional diversity of GnRH.