The Sound of Evolution
Isoproterenol
Mechanism of action:
Isoproterenol is a non-selective β-adrenergic agonist that acts mainly on β₁ and β₂ receptors. It activates β₁ receptors on cardiomyocytes, stimulating adenylyl cyclase and increasing cAMP levels, which enhances calcium influx into the cytoplasm and promotes myocardial contraction, thereby increasing heart rate. It also activates β₂ receptors, causing relaxation of airway smooth muscle and resulting in bronchodilation, while also relaxing vascular smooth muscle and reducing peripheral vascular resistance.
Reference(s):
1. Baker JG et al. (2010). The selectivity of beta-adrenoceptor agonists at human beta1-, beta2- and beta3-adrenoceptors. Br J Pharmacol.
2. Striessnig J et al. (2014). L-type Ca²⁺ channels in heart and brain. Wiley Interdiscip Rev Membr Transp Signal.
3. Harvey RD et al. (2013). CaV1.2 signaling complexes in the heart. J Mol Cell Cardiol.