某些物质与受体结合后,激活磷脂酶C,促进4,5-二磷酸磷脂酰肌醇水解成1,4,5-三磷酸肌醇(IP_3),引起内质网钙库的排空,即钙的动员,钙库的排空进而又可刺激外钙的内流。受体调节的钙内流主要受钙库的排空控制。实验表明,激素敏感的钙库处于排空状态时较易与细胞外 When certain substances are bound to receptors, phospholipase C is activated to promote the hydrolysis of 4,5-diphosphatidylinositol to inositol 1,4,5-triphosphate (IP_3), resulting in the emptying of the endoplasmic reticulum calcium pool , That is, mobilization of calcium, emptying of calcium reservoir and then can stimulate calcium influx. Receptor-mediated calcium influx is mainly controlled by emptying of the calcium pool. Experiments show that hormone-sensitive calcium pool in the emptying state easier with the extracellular