A COMPARISON OF THE CARDIOVASCULAR, RENAL, AND CORONARY EFFECTS OF DOPAMINE AND MONENSIN IN ENDOTOXIC-SHOCK

  • 1 January 1981
    • journal article
    • research article
    • Vol. 8  (4) , 451-464
Abstract
In anesthetized dogs the cardiovascular effects were compared of dopamine and monensin (a carboxylic ionophore) in normal and Escherichia coli endotoxin-induced shock conditions. In control animals, monensin increased cardiac contractility, cardiac output, systemic blood pressure and coronary blood flow in a dose-dependent manner, but had little or no effect on heart rate. Unlike dopamine, which selectively increased renal blood flow, monensin did not affect renal blood flow in doses that produced a maximal increase in coronary blood flow or other hemodynamic effects. The duration of action of monensin was > 2 h. Both dopamine and monensin reversed the cardiac depression and hypotension produced by E. coli endotoxin, and in these experiments the duration of action of monensin was > 2 h. Regional blood flow measurements with the radioactive microsphere (15 .mu.) technique demonstrated a marked decrease in organ blood flows at 60 min postendotoxin, but some recovery was observed at 90 min. In the left ventricle, reduction of flow to the endocardial region was greater than to the epicardium. In dogs with endotoxic shock, monensin produced a significant increase in organ blood flows towards or even above control values.