Cardiac myocyte plasma membrane (sarcolemma)

The cardiac myocyte cell membrane (commonly called the sarcolemma) is the specialized lipid bilayer enclosing the cytoplasm of cardiac muscle cells (cardiomyocytes)[4][1]. This membrane contains integral and peripheral proteins essential for generating and propagating electrical signals, maintaining structural integrity, mediating excitation-contraction coupling, and supporting intercellular communication[3][7][10]. Key components include ion channels (e.g., voltage-gated sodium, calcium, potassium channels), gap junctions and desmosomes at the intercalated discs, and specialized regions such as transverse tubules (t-tubules)[1][4][7]. The membrane is crucial for the synchronized contraction of myocardial tissue that enables effective heart pumping. The sarcolemma is highly specialized and differs from skeletal muscle plasma membranes in its interconnections (intercalated discs) and ion channel composition (notably, L-type calcium channels are concentrated at t-tubules and near ryanodine receptors for efficient calcium signaling)[4][7]. The functional unit for contraction is dependent on the coordinated action of membrane ion channels and associated proteins (such as ankyrin, spectrin, SNAREs for protein localization and trafficking)[6][9]. Many heart diseases arise from mutations or dysfunctions in membrane-associated proteins, not the membrane per se, but in its protein complexes[5][8]. In summary, “cardiac myocyte cell membranes” refers to a complex structural feature composed of many therapeutically relevant proteins but is not itself a single target, molecule, or receptor and should be considered inaccurate or too broad for structured molecular drug targeting.

Other names

sarcolemmacardiac sarcolemmamembrane of cardiac myocytecardiomyocyte plasma membrane

None directly; drugs act via modulation of specific ion channels or membrane receptors (e.g., sodium channel blockade, calcium channel inhibition)