AT1-receptor blockade in experimental myocardial ischemia/reperfusion.

The renin-angiotensin system is activated during myocardial ischemia, and angiotensin II is locally formed in ischemic hearts. At least four angiotensin II receptor subtypes have been identified, the AT1- and the AT2-receptor being the most prominent in the cardiovascular system. AT1-receptor blockade--like inhibition of the angiotensin-converting-enzyme (ACE)--limits infarct size, improves functional recovery following myocardial ischemia and attenuates ventricular remodeling, post-myocardial infarction and the resulting development of heart failure. The potential mechanisms responsible for the cardioprotection by AT1-receptor blockade remain to be elucidated in detail, but appear to involve AT2-receptor activation and--like ACE-inhibitors--bradykinin and prostaglandins. Combined treatment with ACE-inhibitors and AT1-receptor blockers has the potential to further reduce infarct size and improve ventricular remodeling over each monotherapy alone.