monodehydroascorbate and Coronary-Vasospasm

The purpose of this study is to assess the effect of beta1-selective blocker on coronary vasospasm.. Balloon epicardial coronary artery endothelial denudation was performed at the left anterior descending coronary artery every 2 weeks for a total of 4 times in pigs. Changes in denuded site diameter and left anterior descending coronary artery blood flow caused by acetylcholine or serotonin were assessed before each endothelial denudation and at week 8 in untreated pigs (ED group) and in those treated with metoprolol (Meto group) or propranolol (Pro group).. In the ED group, decreased blood flow response to acetylcholine enhanced from -20+/-10% before the first ED to -100% (i.e. zero flow) at week 8 without denuded site narrowing, suggesting microvascular spasm, and serotonin-induced left anterior descending coronary artery diameter reduction at week 8 was -92+/-15%. In the Pro group, blood flow reduction by acetylcholine and left anterior descending coronary artery diameter reduction by serotonin did not change compared with those of the ED group. In the Meto group however, blood flow reduction by acetylcholine (week 8, -70+/-16%) and left anterior descending coronary artery diameter reduction by serotonin (week 8, -64+/-15%) were blunted (P<0.01) compared with those of ED and Pro groups.. The beta1-selective blocker metoprolol was effective to prevent coronary vasospasm.

Topics: Acetylcholine; Adrenergic beta-1 Receptor Antagonists; Adrenergic beta-Antagonists; Animals; Cholinergic Agents; Coronary Angiography; Coronary Vasospasm; Coronary Vessels; Dehydroascorbic Acid; Disease Models, Animal; Laser-Doppler Flowmetry; Metoprolol; Nitric Oxide; Propranolol; Serotonin; Serotonin Agents; Swine