Beneficial actions of bevantolol on subendocardial blood flow and contractile function in ischemic myocardium.
The effect of a new cardioselective beta adrenergic antagonist, bevantolol (CI-775), on regional myocardial blood flow and contractile function distal to a severe flow-limiting stenosis of the left circumflex coronary artery was studied in open-chest dogs. Bevantolol (1 mg/kg, i.v.) or saline was administered 30 min after production of left circumflex stenosis sufficient to reduce resting coronary blood flow and contractile force approximately 40%. Regional myocardial blood flow and contractile force were measured with radiolabeled microspheres and Brodie-Walton strain gauge arches, respectively. No significant changes were observed in the saline-treated group. Following bevantolol treatment subendocardial blood flow (1.30 +/- 0.29 to 0.93 +/- 0.19 ml/min/g) and contractile force decreased (11.4 +/- 4.4%) significantly (p less than 0.05) in nonischemic myocardium. Subendocardial blood flow (0.59 +/- 0.14 to 0.81 +/- 0.14 ml/min/g) and contractile force increased (29.3 +/- 3.6%) significantly (p less than 0.05) in ischemic myocardium. These results suggest that bevantolol produces a favorable redistribution of flow to ischemic subendocardium. The increase in flow results in an improvement of contractile function in the ischemic region.
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D003326:Coronary Circulation / Q000187:drug effects*; D003327:Coronary Disease / Q000503:physiopathology*; D004285:Dogs; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D011412:Propanolamines / Q000494:pharmacology*
D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; C021148:bevantolol