Single-pass gill extraction and tissue distribution of atrial natriuretic peptide in trout.
Single-pass gill extraction and tissue distribution of atrial natriuretic peptide in trout.
复制标题
鳟鱼心房钠尿肽的单次鳃提取和组织分布。
作者：
K. Olson;D. Duff
本实验描述了一种新的方法，以定量心房利钠肽（125 I-ANP）提取血浆中的一个单一的过境通过鳃血管的未麻醉鳟鱼。注射125 I-ANP后1 h，测定125 I相对于惰性细胞外间隙标记物58 Co-EDTA的组织分布。单通提取125 I-ANP的鳃是60%，在对照鱼，它下降到18%，在鱼以前注射生理盐水，并成为阴性（相对于58钴-EDTA）处理后的清除（C型）受体抑制剂SC 46542。大约90%的125 I-ANP丸注入到控制鳟鱼从循环中删除2分钟内。125 I浓度在鳃组织中是近7倍大于预测的58钴-EDTA空间。125 I还集中在脑（2X）、胆囊、胃肠道和眼（均为1X）。SC 46542将鳃125 I结合从58 Co-EDTA空间的7倍减少到1倍，并增加125 I在心脏、肾脏、脂肪和骨骼肌中的累积。离体灌流鳃对~（125）I-ANP的提取率为53%，与体内实验结果相似。这些结果表明，鳃是从鳟鱼血浆中去除ANP的主要场所，C型受体在此过程中占主导地位。
A new method is described in the present experiments to quantify atrial natriuretic peptide (125I-ANP) extraction from plasma in a single transit through the gill vasculature of an unanesthetized trout. Tissue distribution of 125I relative to an inert extracellular space marker, 58Co-EDTA, was also measured 1 h after injection of 125I-ANP. Single-pass extraction of 125I-ANP by the gill was 60% in control fish; it fell to 18% in fish previously injected with saline and became negative (relative to 58Co-EDTA) after treatment with the clearance (C-type) receptor inhibitor SC 46542. Approximately 90% of a 125I-ANP bolus injected into control trout is removed from the circulation within 2 min. 125I concentration in gill tissue was nearly seven times greater than that predicted by the 58Co-EDTA space. 125I was also concentrated in brain (2X), gallbladder, gastrointestinal tract, and eye (all 1X). SC 46542 decreased gill 125I binding from seven times to one times the 58Co-EDTA space and increased 125I accumulation in heart, kidney, fat, and skeletal muscle. Extraction of 125I-ANP by the isolated perfused gill was 53%, similar to that observed in vivo. These results show that the gill is a major site for ANP removal from trout plasma and that C-type receptors are predominant in this process.