C-type natriuretic peptie as a paracrine and an endocrine hormone

C 型钠尿肽作为旁分泌激素和内分泌激素

基本信息

批准号：
06454020
负责人：
TAKEI Yoshio
金额：
$ 4.61万
依托单位：
Ocean Research Institute University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

1. Plasma atrial and ventricular natriuretic peptide (ANP and VNP) levels increased transiently after transfer of eels from fresh water (FW) to seawater (SW). Injection of hypertonic solutions markedly increased plasma ANP and VNP levels, but blood volume expanasion was a much smaller secretagogue in the eel. ANP and VNP secretion increased in isolated, perfused eel heart after prefusate osmolality was increased These results show that osmotic requlation dominates volemic requlation for ANP and VNP secretion in the eel, and osmotic stimulus was perceived by cardiocytes themselves.2. Whole-body autoradiography revealed dense accumulation of ^<125>I-eel ANP in the gill. Radio-ligand binding assay showed that most ANP receptors in the eel gill are clearance type NPR-C ; however, guanylate cyclase-coupled, CNP-specific NPR-B was also present in the gill of only FW eels. This is consistent with much less expression of NPR-B message in SW eels than in FW eels.3. ANP inhibits drinking and intestinal absorption of water and sodium in both FW and eels. ANP also inhibits secretion of cortisol, a fish mineralocorticoid important for SW adaptation, and causes antidiuresis and natriuresis only in SW eels. It seems that ANP is a sodium extruding hormone in SW fish.4. B-type natriuretic peptide (BNP) was isolated from the cardiac ventricle of bullfrog. Thus semiaquatic amphibians seem to have terapod-type BNP not fish-type VNP in their Ventriles.

1.将鳗鱼从淡水（FW）转移到海水（SW）后，血浆心房和心室钠尿肽（ANP和VNP）水平短暂升高。注射高渗溶液显着增加了鳗鱼血浆 ANP 和 VNP 水平，但血容量扩张的促分泌作用要小得多。预融合液渗透压增加后，离体灌注鳗心脏中ANP和VNP分泌增加。这些结果表明，在鳗鱼中，渗透压调节主导了ANP和VNP分泌的容量调节，并且心肌细胞本身感知到渗透刺激。2．全身放射自显影显示鳃中^ 125 I-鳗鱼ANP密集积聚。放射性配体结合实验表明，鳗鱼鳃中大多数ANP受体为清除型NPR-C；然而，鸟苷酸环化酶偶联的 CNP 特异性 NPR-B 也仅存在于 FW 鳗鱼的鳃中。这与 SW 鳗鱼中 NPR-B 信息的表达比 FW 鳗鱼少得多是一致的。3。 ANP 抑制 FW 和鳗鱼的饮水和肠道对水和钠的吸收。 ANP 还抑制皮质醇（一种对 SW 适应很重要的鱼类盐皮质激素）的分泌，并且仅在 SW 鳗鱼中引起抗利尿和尿钠排泄。看来ANP是西南鱼的排钠激素。4． B型利钠肽（BNP）是从牛蛙的心室中分离出来的。因此，半水生两栖动物的心室中似乎具有四足动物型 BNP，而不是鱼类型 VNP。