What type of receptor is involved in the positive ionotropic effect of epinephrine or norepinephrine on the heart contractility?

Question

Quizplus · Accepted Answer

The positive ionotropic effect of epinephrine or norepinephrine on the heart contractility is mediated by G protein-coupled receptor activation. Specifically, they bind to beta-1 adrenergic receptors, which activate the G protein Gs, leading to an increase in cyclic adenosine monophosphate (cAMP) and subsequent activation of protein kinase A (PKA). PKA then phosphorylates key calcium-handling proteins in the cardiomyocyte, leading to increased calcium influx and release from intracellular stores, ultimately resulting in enhanced contractility.

What Type of Receptor Is Involved in the Positive Ionotropic