β-adrenergic regulation of Ca2+ signaling in heart cells.

β-adrenergic receptors (βARs) play significant roles in regulating Ca²⁺ signaling in cardiac myocytes, thus holding a key function in modulating heart performance. βARs regulate the influx of extracellular Ca²⁺ and the release and uptake of Ca²⁺ from the sarcoplasmic reticulum (SR) by activating key components such as L-type calcium channels (LTCCs), ryanodine receptors (RyRs) and phospholamban (PLN), mediated by the phosphorylation actions by protein kinase A (PKA). In cardiac myocytes, the presence of β₂AR provides a protective mechanism against potential overstimulation of β₁AR, which may aid in the restoration of cardiac dysfunctions. Understanding the Ca²⁺ regulatory signaling pathways of βARs in cardiac myocytes and the differences among various βAR subtypes are crucial in cardiology and hold great potential for developing treatments for heart diseases.