Hemodynamic Effects of Infusions of Epinephrine and Arterenol in Normal and Shocked Dogs

Abstract

Levarterenol and l-epinephrine were infused into dogs and the effect on cardiac output and other measurements derived by the dye dilution technique were observed. In contrast to epinephrine, arterenol decreased or left unchanged the cardiac output, suggesting that there is not a species difference between dog and man and that arterenol and epinephrine are qualitatively different in their cardiovascular effects. In previous studies which disagree with this conclusion arterenol was administered by a rapid intravenous injection. The changes in cardiac output correlated well with the changes in total peripheral resistance, and the rise in peripheral resistance induced by arterenol is suggested as the factor which in the intact animal modifies the positive inotropic effect of arterenol apparent in isolated hearts. Circulating plasma volume, intrathoracic blood volume and cardiac output also rose and fell together. No difference in response to the two agents was apparent between normal dogs and those in which cardiogenic shock had been induced.