D'Antonio M, Vallarino M, Lovejoy D A, Vandesande F, King J A, Pierantoni R, Peter R E
Department of Zoology, University of Alberta, Edmonton, Canada.
Gen Comp Endocrinol. 1995 Apr;98(1):35-49. doi: 10.1006/gcen.1995.1042.
The distribution of different molecular forms of gonadotropin-releasing hormone (GnRH) in the brain and serum of the spotted dogfish, Scyliorhinus canicula, was investigated by an indirect immunofluorescence method, using antisera against salmon (s-), chicken-II (cII-) and mammalian (m-) GnRHs, and by reverse-phase high-performance liquid chromatography (RP-HPLC) coupled with radioimmunoassays. Five GnRH molecular forms were demonstrated on the basis of the retention time in the RP-HPLC system. The characteristics of four of these GnRH peptides are consistent with those of m-, cII-, dogfish (df-), and sGnRH. The fifth form appears to be novel. Immunoreactive sGnRH structures were confined to the diencephalon; whereas cIIGnRH and mGnRH were found in the telencephalon and diencephalon. cIIGnRH- and dfGnRH-like molecules were detected in the serum. Moreover, a specific, low-affinity GnRH binding protein (GnRH-BP) was found in the serum of the spotted dogfish. The binding of [125I]sGnRHA to the serum GnRH-BP was dependent on incubation time, equilibrium being reached within 1 hr at 4 degrees; binding was rapid and completely reversible. Scatchard analysis yielded a linear plot with a Kd of 7.9 x 10(-7) M. The presence of a GnRH-BP in spotted dogfish serum suggests a probable action of GnRH via the general circulation.
采用间接免疫荧光法，使用抗鲑鱼（s-）、鸡-II（cII-）和哺乳动物（m-）促性腺激素释放激素（GnRH）的抗血清，以及结合放射免疫分析的反相高效液相色谱法（RP-HPLC），研究了斑点角鲨（Scyliorhinus canicula）大脑和血清中不同分子形式的GnRH的分布。基于RP-HPLC系统中的保留时间，证实了五种GnRH分子形式。其中四种GnRH肽的特征与m-、cII-、角鲨（df-）和sGnRH的特征一致。第五种形式似乎是新的。免疫反应性sGnRH结构局限于间脑；而cIIGnRH和mGnRH则在端脑和间脑中发现。在血清中检测到cIIGnRH-和dfGnRH样分子。此外，在斑点角鲨的血清中发现了一种特异性、低亲和力的GnRH结合蛋白（GnRH-BP）。[125I]sGnRHA与血清GnRH-BP的结合取决于孵育时间，在4℃下1小时内达到平衡；结合迅速且完全可逆。Scatchard分析得到一条线性图，Kd为7.9×10^(-7) M。斑点角鲨血清中存在GnRH-BP表明GnRH可能通过全身循环发挥作用。
