Effects ofβ-Adrenoceptor Subtypes on Cardiac Function in Myocardial Infarction Rats Exposed to Fine Particulate Matter (PM2.5)

The pathophysiological mechanisms of heart failure (HF) stems were mainly from longstanding overactivation of the sympathetic nervous system and renin-angiotensin-aldosterone system. Recent studies highlighted the potential benefits ofβ1-adrenoceptor (β1-AR) blocker combined withβ2-adrenergic receptor (β2-AR) agonist in patients with HF. Long-term exposure to fine particulate air pollution, such as particulate matter ≤ 2.5 μm in diameter (PM2.5), has been found associated with acute myocardial infarction (AMI) which is the most common cause of congestive HF. In this study, we have investigated the effect of combined metoprolol and terbutaline on cardiac function in a rat model of AMI exposed to PM2.5. Our results demonstrated that short-term exposure to PM2.5contributes to aggravate cardiac function in rats with myocardial infarction. The combined use ofβ1-AR blocker andβ2-AR agonist is superior toβ1-AR blocker alone for the treatment of AMI rats exposed to PM2.5. The combination ofβ1-AR blocker andβ2-AR agonist may decrease the mortality of patients with myocardial infarction who have been exposed to PM2.5.