RT Journal Article SR Electronic T1 HEMODYNAMIC EFFECTS OF ETHACRYNIC ACID IN ANEPHRIC DOGS JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 389 OP 396 VO 176 IS 2 A1 RICHARD IAN OGILVIE A1 JOHN RUEDY YR 1971 UL http://jpet.aspetjournals.org/content/176/2/389.abstract AB Ethacrynic acid (EA) has been found useful in the treatment of acute cardiac failure. It has been assumed that this is due to its prompt and marked diuretic effect which reduces plasma volume and venous return. Because some of our patients in acute cardiac failure responded to EA with a fall in central venous pressure before the onset of diuresis, we postulated a direct action of this agent on capacitance or resistance vessels. To study this possible extrarenal action of EA, dogs were nephrectomized to prevent any diuretic effect of the drug and then given EA, 5 mg/kg, or glucose-water i.v. EA reduced the mean arterial pressure and total peripheral resistance within 20 minutes. These reductions were maximal at 60 minutes, and the values remained significantly below those of the dogs given glucose-water for the two hours of observation. The two groups did not differ significantly in heart rate, cardiac output and central venous pressure at any time. Hematocrit and plasma volume did not change. EA produced similar reductions in systemic arterial pressures and total peripheral resistance and did not reduce central venous pressure in anephric dogs with circulatory volume overload produced by dextran infusions as well as in sham-nephrectomized dogs. These results suggest that EA relaxes vascular smooth muscle and that the predominant effect is on precapillary resistance vessels. © 1971 by The Williams & Wilkins Co.