Myocardial cell sarcolemma (Sarcolemma)

The myocardial cell sarcolemma is the specialized plasma membrane of cardiac muscle cells, consisting of a phospholipid bilayer and an outer glycocalyx. It serves as the critical interface for excitation-contraction coupling, housing the essential ion channels, transporters, and receptors required to generate and propagate cardiac action potentials [3][5]. In pathological states such as myocardial infarction or ischemia-reperfusion injury, the sarcolemma can become compromised by lipid peroxidation, leading to the leakage of intracellular proteins like troponin into the systemic circulation, which serves as a clinical biomarker for cardiac damage [3][7]. While the sarcolemma itself is a cellular structure rather than a single molecular target, it is the primary site of action for numerous pharmacological agents, including beta-blockers, calcium channel blockers, and antiarrhythmics, which modulate heart rate and contractility by acting on membrane-bound proteins [4][6]. Furthermore, the sarcolemma is involved in the pathogenesis of rheumatic fever, where streptococcal antigens may induce an autoimmune cross-reaction against sarcolemmal components [1].

Other names

Cardiomyocyte sarcolemmaMyocardial plasmalemmaMyocardial cell membraneSarcolemmal membrane

Drugs typically interact with the myocardial cell sarcolemma by inhibiting specific proteins embedded within it, such as the sodium-potassium ATPase (inhibited by Digoxin), blocking ion channels like L-type calcium channels (Verapamil) or sodium channels (Lidocaine), or by stabilizing the membrane lipids against oxidative stress (Alpha-tocopherol) [1][3][4].