摘要：自1989年从绵羊下丘脑提取物发现垂体腺苷酸环化酶激活多肽(Pituitary adenylate cyclase activating polyp...自1989年从绵羊下丘脑提取物发现垂体腺苷酸环化酶激活多肽(Pituitary adenylate cyclase activating polypeptide,PACAP)以来(Miyata et al., 1989),已证明它能促进垂体激素释放,同时还具有神经递质、神经调质和神经营养等作用,使对PACAP的研究成为十分活跃的领域.PACAP属于血管活性肠肽(VIP)-胰高血糖素-生长激素释放因子-分泌素家族(Campbell and Scanes,1992)成员,已鉴别出包含27和38个氨基酸两种类型.对原索动物(McRory et al.,1997)、两栖类(蛙)(Alexandre et al.,2000)、爬行类(蜥蜴)(Pohl and Wank,1998)、鸟类(鸡)(McRory et al.,1997),啮齿类(鼠)(Ghatei et al.,1993)等脊椎动物PACAP的研究多集中在结构与进化方面,对功能了解甚少.显示全部
摘要：Changes in the pituitary and serum gonadotropin levels of Cranoglanis bouderius were studied at dif...Changes in the pituitary and serum gonadotropin levels of Cranoglanis bouderius were studied at different stages of ovarian development.Based on African catfish gonadotropin(cfGTH) and its anti-serum(Racf),heterologous radio-immunoassay(RIA) for the gonadotropin(GTH) of Cranoglanis bouderius was developed.The pituitary GTH contents at the late development stage were significantly higher than that at the mature,ovulation or regressed stages,while serum GTH levels at maturation and ovulation were significantly higher than that at late development and regressed stages,Injection of gonadotropin-releasing hormone analogue(GnRH-A) stimulated GTH secretion.Domperidone (DOM) had no effect on the basal serum GTH level.Injection of GnRH-A and DOM significantly enhanced the GTH levels stimulated by GnRH-A alone.These results indicate that GTH release in Cranoglanis bouderius is under the dual regulation of gonadotropin releasing hormone(GnRH) and dopamine(DA) from the hypothalamus,but DA can only inhibit GTH release induced by GnRH and not basal GTH release[Acta Zoologica Sinica 49(3):399-403.2003].显示全部
