Heart's Signaling Symphony: Exploring Cardiac Receptors

Abstract

This overview delves into the intricate interplay between adrenergic and cholinergic receptors in regulating heart function. The sympathetic and parasympathetic nervous systems play a powerful role in controlling cardiac function by activating adrenergic and muscarinic receptors. In the human heart, there exist α1, β1, and β2- adrenoceptors and M2-muscarinic receptors and possibly also (prejunctional) α2-adrenoceptors. The human heart has a very uniform distribution of β1 and β2-adrenoceptors and a heterogeneous distribution of M2-receptors (more receptors in the atria than the ventricles). Heart rate and contraction force increase whenever β1 and β2-adrenoceptors are stimulated, while heart rate and contraction force fall when M2 receptors are stimulated (directly in the atria and indirectly in the ventricles). The distribution of β1 and β2-adrenoceptors in the human heart can be changed by pathological conditions (like heart failure) or pharmacological interventions (like -blocker medication), nevertheless, M2-receptors are much less influenced. The intricate relationships between these receptor systems offer possible cardiovascular disease therapy strategies. More research must be conducted, focused on the complex control mechanisms that regulate cardiac function and pathology, to fully comprehend the subtleties of these signalling pathways and how they affect heart health.