Phylogenetic study on regulation of water balance by biologically active peptide.

1.在文昌鱼的中枢神经系统中，发现6个独立的神经系统分别表达加压素(VP)、催产素(OT)、血管紧张素II、缩胆囊素、尾加压素I和FMRFamide。为免疫反应性内皮素-1(ET-1)和神经垂体激素在大鼠神经叶轴突末梢内的共存提供了证据。失血或脱水后血浆ET-1水平无明显变化，而VP水平显著升高。在神经叶中，脱水后ET-1免疫活性含量下降约50%，而失血大鼠神经叶中ET-1免疫活性含量增加近3倍。在牛蛙的视前核和神经垂体中发现了ET-1免疫阳性反应。免疫反应神经元对应于0T免疫反应神经元的亚群。用放射自显影技术，以ET-1为木素，在牛蛙神经垂体内定位了可能的ET受体。两种轴突的轴突膜上密度最高，轴突内密度最高。用免疫组织化学方法研究了ET样免疫反应物质在牛蛙腺垂体中的分布。ET-3免疫反应阳性细胞与生长激素细胞相对应。未检测到ET-1样免疫反应。脑利钠肽在水充足的日本鹌鹑体内或脑室内给药时，显著增加了水的摄入量。腹腔注射ET-1后，水摄入量略有增加。用免疫组织化学方法研究了9种影响饮酒行为的多肽在大鼠穹隆下器的分布。P物质或亮氨酸脑啡肽阳性纤维见于SFO的前外侧区，而神经降压素和促黄体生成素释放激素阳性纤维见于SFO的背尾部。

1. In the central nervous system of the amphioxus, six separate neuronal systems were found showing immunoreactivity for vasopressin (VP), oxytocin (OT), angiotensin II, cholecystokinin, urotensin I, and FMRFamide, respectively.2. Evidence was provided for the intragranular colocalization of immunoreactive endothelin-1 (ET-1) and neurohypophysial hormones in the axon terminal of the rat neural lobe.3. Plasma levels of immunoreactive ET-1 were not altered following hemorrhage or dehydration, whereas those of immunoreactive VP were remarkably increased. In the neural lobe, the immunoreactive ET-1 contents decreased by about 50% after dehydration, but increased nearly three-fold in hemorrhaged rats.4. ET-1-immunoreactivity was found in the preoptic nucleus and the neurohypophysis of the bullfrog. Immunoreacted neurons corresponded to a subpolpulation of 0T-immunoreactive neurons.5. Putative receptors for ET were localized autoradiographically in the bullfrog neurohypophysis using [^<125>I]ET-1 as a lignad. The highest densities were found on the axon membrane of two types of the axon, and within these axons.6. The distribution of ET-like immunoreactivity was studied in the bullfrog adenohypophysis. ET-3-immunoreactive cells were found to correspond to somatotrophs. ET-1-like immunoreactivity was not detected.7. Brain natriuretic peptide elicited a significant increase in water intake, when administered intraperitoneally or intracerebro-ventricularly, in the water-replete Japanese quail. Intraperitoneal injection of ET-1 slightly enhanced water intake.8. Immunohistochemical distribution of nine peptides, which are able to affect drinking behavior, was investigated in the rat subfornical organ (SFO). Fibers immunoreactive for substance P or Leu-enkephalin were found in the anterolateral area of the SFO, whereas fibers immunoreactive for neurotensin and LH-releasing hormone were detected in the dorsocaudal region of the SFO.