title: The effect of propranolol on microvascular injury in acute myocardial ischemia.
abstract: The purpose of this study was to determine whether propranolol, which has been shown to reduce the extent of myocardial infarction, reduces microvascular injury which may play a role in exacerbating ischemia. Saline (10 dogs) or propranolol (2 mg/kg i.v., 7 dogs) was injected prior to a one hour occlusion of the left anterior descending coronary artery. Carbon black (1 ml/kg), which labels damaged and leaky vessels, was injected 5 min after release of the occlusion and allowed to circulate for two hours. By morphometric analysis of 1 micron thick sections, 75 +/- 12% of vessels and 84 +/- 7% of myocardial cells showed damage in untreated dogs; only 2 +/- 1% of vessels and 9 +/- 8% of myocardial cells showed damage in the propranolol-treated dogs (P less than 0.001). The number of carbon black-labeled vessels/10 fields/biopsy from comparable areas of ischemic tissue was 55 +/- 7 in untreated dogs and 27 +/- 3 in propranolol-treated dogs (P less than 0.001). The results suggest that propranolol not only protects the ischemic myocardial cell, but also significantly decreases the ischemic microvascular changes.
mesh_terms: D000208:Acute Disease; D000818:Animals; D002244:Carbon; D003327:Coronary Disease / Q000150:complications*; D004285:Dogs; D004562:Electrocardiography; D005260:Female; D008297:Male; D008833:Microcirculation / Q000187:drug effects / Q000293:injuries*; D011433:Propranolol / Q000494:pharmacology*; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D012965:Sodium Chloride; D002244:Carbon; D011433:Propranolol