Effects of a new calcium antagonist, CD-832, on experimental coronary artery spasm in miniature pigs

The effects of a new calcium antagonist, CD-832, on experimental coronary artery spasms were studied in Gottingen miniature pigs. Pigs underwent endothelial denudation at the left anterior descending coronary artery using a balloon catheter. Changes in the diameter of the denuded and nondenuded site in response to an intracoronary administration of serotonin (10 µg/kg) or histamine (10 µg/kg) were assessed quantitatively by selective coronary arteriography 1 week after endothelial denudation. Percent reductions of the coronary artery diameter induced by serotonin or histamine in the denuded site were significantly greater than those in the nondenuded site (p<0.01). Coronary artery spasm induced by serotonin or histamine in the denuded site was attenuated in a dose-dependent manner by intravenous infusion of CD-832 (10 and 30 µg/kg/min) or nifedipine (1 and 3 µg/kg/min). The degrees of inhibition of coronary artery spasm by CD-832 were similar to those produced by nifedipine. CD-832 and nifedipine at the high dose caused comparable increases in the basal coronary artery diameter. These results suggest that CD-832 may be a useful drug for the treatment of coronary artery spasm.