Inhibition of goby posterior intestinal NaCl absorption by natriuretic peptides and by cardiac extracts.
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.
Loretz
C A
CA
Department of Biological Sciences, State University of New York at Buffalo 14260-1300, USA.
D000818:Animals; D002457:Cell Extracts / Q000494:pharmacology; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D005399:Fishes / Q000378:metabolism*; D007408:Intestinal Absorption / Q000502:physiology*; D017136:Ion Transport / Q000187:drug effects; D008353:Mannitol / Q000378:metabolism; D008954:Models, Biological; D009206:Myocardium / Q000737:chemistry*; D045283:Natriuretic Agents / Q000494:pharmacology*; D010455:Peptides / Q000494:pharmacology; D012965:Sodium Chloride / Q000378:metabolism*; D014882:Water-Electrolyte Balance / Q000187:drug effects / Q000502:physiology
D002457:Cell Extracts; D045283:Natriuretic Agents; D010455:Peptides; C016276:8-bromocyclic GMP; D008353:Mannitol; D012965:Sodium Chloride; D006152:Cyclic GMP