Brandt N R, Kawamoto R M, Caswell A H
J Recept Res. 1985;5(2-3):155-70. doi: 10.3109/10799898509041877.
Receptors for the dihydropyridine class of Ca2+ channel antagonists are present on transverse tubules isolated by mechanical disruption of skeletal muscle triads. These observations account for the previously reported presence of nitrendipine binding sites in heavy sarcoplasmic reticulum. Nitrendipine receptors were not found in the terminal cisternae after disruption of the triad junctions. The number of sites in junctional T-tubules (27 pmol/mg) is only half that reported for transverse tubules isolated as free vesicles (pmol/mg). The presence of nitrendipine receptors in that region of the transverse tubules held in close apposition to the SR cisternae is consistent with the architectural requirements for the Ca2+ induced Ca2+ release phenomenon to be the mechanism of excitation-contraction coupling.
通过机械破坏骨骼肌三联体分离出的横管上存在二氢吡啶类钙离子通道拮抗剂的受体。这些观察结果解释了先前报道的在重肌浆网中存在尼群地平结合位点的现象。三联体连接破坏后，终池未发现尼群地平受体。连接性横管中的位点数量（27 pmol/mg）仅为报告的作为游离囊泡分离出的横管（pmol/mg）的一半。横管中与肌浆网终池紧密相邻区域存在尼群地平受体，这与钙离子诱导钙离子释放现象作为兴奋 - 收缩偶联机制的结构要求相一致。
