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

1.在文昌鱼的中枢神经系统中，有6个独立的神经元系统分别对血管加压素（VP）、催产素（OT）、血管紧张素II、胆囊收缩素、尾加压素I和FMRFamide呈免疫反应性.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终末的颗粒内共定位提供了证据.出血或脱水后血浆ET-1水平无明显变化，而VP水平明显升高。在神经叶中，ET-1的免疫反应性含量在脱水后下降了约50%，但在脱水后增加了近3倍.在牛蛙的视前核和神经垂体中发现了ET-1的免疫反应。免疫反应神经元对应于0 T免疫反应神经元的亚群.以[^ I]ET-1为配体，用放射自显影法在牛蛙神经垂体中定位了ET的假定受体<125>。两种类型轴突的轴突膜上和轴突内部密度最高.本文研究了牛蛙腺垂体内ET样免疫反应阳性物质的分布。ET-3免疫反应阳性细胞被发现对应于生长激素细胞。未检测到ET-1样免疫反应.脑利钠肽引起了显着增加水的摄入量，当给药intraperitoneal或脑室内，在水充满日本鹌鹑。腹腔内注射ET-1可轻度增强大鼠的饮水量.本实验研究了9种影响饮水行为的多肽在大鼠穹窿下器（SFO）中的免疫组织化学分布。纤维P物质或亮氨酸脑啡肽的免疫反应被发现在前外侧区的SFO，而神经降压素和LH-释放激素的免疫反应被检测到在背尾侧区域的SFO。

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.