title: Cell membrane responsiveness and excitation-contraction coupling in smooth muscle.
abstract: In this study of the excitation-contraction coupling in arterial smooth-muscle cells, the relations between changes of the membrane potential, force development, and 45Ca exchange have been investigated. It is proposed that the cell membrane plays a primary role by regulating the Ca entry into smooth-muscle cells and by extruding the excess cytoplasmic Ca. The possible relation between the receptor-operated channels and the sarcoplasmic reticulum has been discussed, and the peculiar differences between exogenous noradrenaline and noradrenaline released from the nerve terminals have been described.
mesh_terms: D000818:Animals; D001158:Arteries / Q000502:physiology; D002118:Calcium / Q000378:metabolism / Q000502:physiology; D002132:Calcium Radioisotopes; D002462:Cell Membrane / Q000502:physiology; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D009474:Neurons / Q000378:metabolism; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000378:metabolism
chemical_list: D002132:Calcium Radioisotopes; D007473:Ion Channels; D002118:Calcium