Loretz C A
Department of Biological Sciences, State University of New York at Buffalo 14260-1300, USA.
J Comp Physiol B. 1996;166(8):484-91. doi: 10.1007/BF02338291.
Natriuretic peptides abolish active Na+ and Cl- absorption across the posterior intestine of the euryhaline goby Gillichthys mirabilis. Inhibition by eel and human natriuretic peptides is dose-dependent with the following sequence of potencies based on experimentally determined ID50 values for inhibition of short-circuit current: eel ventricular natriuretic peptide (78 nmol.l-1), eel atrial natriuretic peptide (156 nmol.l-1), human brain natriuretic peptide (326 nmol.l-1), human alpha atrial natriuretic peptide (1.05 mumol.l-1), and eel C-type natriuretic peptide (75 mumol.l-1). Natriuretic peptides also significantly increase transcellular conductance. The observed sequence of natriuretic peptide potencies is suggestive of cellular mediation by GC-A-type NP-R1 receptors in this tissue; as expected for guanylyl-cyclase-coupled NP-R1 receptors, cyclic GMP mimics the action of natriuretic peptides on the goby intestine. Crude aqueous extracts of goby atrium and ventricle inhibited short circuit current and increased tissue conductance in a dose-dependent manner. Ventricular extract was more potent than atrial extract on both a per organ and per milligram basis.
利尿钠肽可消除广盐性虾虎鱼（奇异吉利虾虎鱼）后肠对Na⁺和Cl⁻的主动吸收。鳗鱼和人类利尿钠肽的抑制作用呈剂量依赖性，根据实验测定的抑制短路电流的ID50值，其效力顺序如下：鳗鱼心室利尿钠肽（78 nmol·l⁻¹）、鳗鱼心房利尿钠肽（156 nmol·l⁻¹）、人类脑利尿钠肽（326 nmol·l⁻¹）、人类α-心房利尿钠肽（1.05 μmol·l⁻¹）和鳗鱼C型利尿钠肽（75 μmol·l⁻¹）。利尿钠肽还显著增加跨细胞电导。所观察到的利尿钠肽效力顺序提示该组织中存在由GC-A型NP-R1受体介导的细胞作用；正如对鸟苷酸环化酶偶联的NP-R1受体所预期的那样，环磷酸鸟苷模拟了利尿钠肽对虾虎鱼肠道的作用。虾虎鱼心房和心室的粗水提取物以剂量依赖性方式抑制短路电流并增加组织电导。无论是按每个器官还是每毫克计算，心室提取物的效力都比心房提取物更强。
