Effects of atriopeptin III on renal function, regional blood flows and left ventricular function in conscious dogs in presence or absence of hypovolaemia.
The effects of atriopeptin III (AP III) on the left ventricular and renal functions were studied in thirteen chronically instrumented conscious dogs and compared to those of the solvent (saline). In the normovolaemic state, an AP III infusion (1 microgram kg-1 min-1 i.v.) had no effects on heart rate, on mean arterial or left ventricular pressure, on (dP/dt) Max (2989 +/- 119 vs. 3007 +/- 155 mmHg s-1; NS) or on the relaxation rate. The left ventricular endocardial and epicardial coronary blood flows (radioactive microspheres) and the renal flow in the outer cortex (707-683 ml (min-1 100 g-1); NS) or in the inner cortex (563-570; NS) were also insignificantly affected by AP III infusion. However, AP III increased urinary flow from 24 +/- 6 to 36 +/- 7 ml h-1 (P less than 0.025) and the Na+ and Cl- excretions by 92 and 98%, respectively, (P less than 0.025 and P less than 0.01 vs. saline group) without altering significantly K+, urea and creatinine eliminations. In the moderately hypovolaemic state (mean reduction in renal flow: outer cortex - 15%; P less than 0.05, inner cortex - 5%; NS), AP III infusion at two doses (1 and 3 micrograms kg-1 min-1) still had no effects on arterial pressure and on the indexes of left ventricular inotropic state and relaxation but in this setting, the diuretic effect of AP III became variable. Five dogs markedly increased their excretion of water, Na+ and Cl- whereas no change was noted in the seven remaining dogs.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D004231:Diuresis / Q000187:drug effects; D004285:Dogs; D005260:Female; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects; D007668:Kidney / Q000187:drug effects* / Q000502:physiology; D009200:Myocardial Contraction / Q000187:drug effects; D012039:Regional Blood Flow / Q000187:drug effects; D012769:Shock / Q000503:physiopathology*
D009320:Atrial Natriuretic Factor