SYSTEMIC AND CORONARY HEMODYNAMIC EFFECTS OF HEXOBENDINE AND ITS INTERACTION WITH ADENOSINE AND AMINOPHYLLINE

¹ Cardiovascular Research Laboratory, Department of Medicine, University of Wisconsin Medical School, Madison, Wisconsin

The systemic and coronary hemodynamic effects of hexobendine have been investigated in dogs and in man. In both it produced an increase in coronary blood flow and coronary sinus oxygen content, with a decrease in coronary vascular resistance. The dose (per kilogram) was larger in dogs and cardiac output increased, but in man it did not. Hexobendine augments the coronary vasodilator activity of adenosine. This effect is marked when adenosine is administered into the right atrium and less when adenosine is infused into the left atrium or the coronary artery. This suggests that the lung normally destroys adenosine and that this is prevented to a significant degree by hexobendine. Black Labrador dogs, although not a pure breed themselves, differed from other mongrel dogs in that their coronary flow increased more after right atrial infusion of adenosine, and hexobendine had less enhancing effect on the change produced in their coronary flow by right atrial adenosine infusion.