Cardiac myocyte membrane

The cardiac myocyte membrane, also known as the sarcolemma, is the specialized plasma membrane of heart muscle cells that maintains the electrochemical gradients necessary for cardiac contraction [StatPearls, 2023]. It consists of a lipid bilayer embedded with a diverse array of proteins, including ion channels, pumps, and receptors that facilitate excitation-contraction coupling [NCBI, 2022]. This structure is vital for signal transduction, allowing the heart to respond to autonomic nervous system inputs via adrenergic and cholinergic receptors [PubMed, 2021]. In pathological states like myocardial infarction, the integrity of the sarcolemma is compromised, leading to the release of diagnostic enzymes and proteins into the circulation [NIH, 2023]. While not a single molecular target, the sarcolemma serves as the functional platform for numerous cardiovascular drugs, such as antiarrhythmics and inotropes, which modulate the activity of its constituent proteins [PubChem]. Consequently, it is a focal point for understanding both cardiac physiology and the mechanism of action for many life-saving therapies.

Other names

SarcolemmaCardiomyocyte membraneMyocardial cell membrane

Drugs interact with specific proteins embedded within the cardiac myocyte membrane to modulate ion flux (e.g., sodium, potassium, calcium) or intracellular signaling cascades (e.g., cAMP), thereby altering heart rate, rhythm, and contractile force [StatPearls, 2023].