钙是肌肉兴奋—收缩的偶联离子,它在调节心肌收缩力和血管平滑肌张力上起着十分重要的作用。由于心肌和平滑肌的肌浆网内贮存 Ca~(++)较少,因此肌细胞内的 Ca~(++)主要依赖于细胞外液中的 Ca~(++)通过细胞膜上的钙通道内流。所以,调节细胞膜上的钙通道开放和关闭就可影响心肌收缩力和血管张力,从而调节心血管功能。 Calcium is a muscle-excited-contractile coupling ion that plays a very important role in regulating myocardial contractility and vascular smooth muscle tone. Due to the small amount of Ca ~ (++) stored in the sarcoplasmic reticulum of myocardium and smooth muscle, Ca ~ (++) in muscle cells mainly depends on Ca ~ (++) in extracellular fluid through calcium channel Internal flow. Therefore, the regulation of cell membrane calcium channel opening and closing can affect myocardial contractility and vascular tone, and thus regulate cardiovascular function.