Apoptosis after reperfused myocardial infarction: Role of angiotensin II.
Angiotensin II (Ang II) plays a significant role in apoptosis after myocardial infarction (MI) and reperfused MI. Cumulative evidence suggests that Ang II is a major contributor to cardiomyocyte (CM) apoptosis and left ventricular (LV) dysfunction after acute reperfused MI and that apoptosis mediates a major portion of early LV dysfunction. Importantly, blockade of the Ang II type 1 receptor (AT(1)R) limits CM apoptosis and LV dysfunction after acute reperfused MI. Ang II type 2 receptor activation during AT(1)R blockade contributes to these beneficial effects. The role of Ang II and apoptosis in chronic LV remodelling, healing and post-MI heart failure is more complex and involves effects on the CMs, fibroblasts and vascular cells. The long-term effects of agents targeting apoptosis after reperfused MI, including AT(1)R blockade, on apoptosis in different cell types, windows of enhanced apoptosis and the appropriate timing of therapy need to be considered.
Jugdutt
Bodh I
BI
Division of Cardiology, Department of Medicine and the Cardiovascular Research Group, Faculty of Medicine, University of Alberta, Edmonton, Alberta.