Attenuation of Myocardial Stunning by Angiotensin II Type 1 Receptor Blockade with Candesartan: Role of the Type 2 Receptor

摘要

We assessed the effect of the angiotensin II (Angll) type 1 receptor (AT_1R) blocker, candesartan on hemodynamics and LV systolic and diastolic function, infarct size and regional AT_1R and Angll type 2 receptor (AT_2R) proteins after regional anterior ischemia-reperfusion (IR) (60 min ischemia, 90 min reperfusion) in Sprague-Dawley rats randomized to intravenous candesartan or saline (control) before IR. Compared to the controls, candesartan significantly (P<0.001) decreased infarct size, limited increases in left atrial pressure, improved positive and negative LV dP/dt, normalized ejection fraction, improved diastolic function, limited infarct expansion and increased AT,R protein in the reperfused zone, with no change in AT_1R after IR. The results suggest that AT_2R upregulation during AT_1R blockade might contribute in limiting myocardial stunning during IR in the rat.