细胞内贮存钙释放的机制

Mechanisms of Mobilization of Intracellular Stored Calcium

细胞内贮存钙的释放主要由１，４，５－三磷酸肌醇（ＩＰ_３）受体系统和ｒｙａｎｏｄｉｎｅ（暂译为兰尼定）受体系统调控。前者通过ＩＰ_３与其受体结合后，诱发细胞内钙释放；后者通过复杂的机制调节环腺苷二磷酸核糖（ｃＡＤＰＲ）含量，由ｃＡＤＰＲ直接或间接作用于ｒｙａｎｏｄｉｎｅ受体，进而启动由Ｃａ^（２＋）诱发的Ｃａ^（２＋）释放机制。上述两系统之间相互作用，共同调节细胞内贮存钙的释放。

The release of intracellular stored Ca2+ is mainly regulated by an inositol 1,4,5 triphosphate(IP_3 ) receptor system and a ryanodine receptor system. The former induces Ca2+ release directly when the receptors are bound to IP_3.The later may function through the Ca2+ induced Ca2+ release mechanism when the ryanodine receptors are activated.Cyclic ADP ribose,a metabolite of NAD+ which is regulated by complicated mechanisms,is one of the most important factors causing activation of ryanodine receptors.The two systems may interact with each other to regulate Ca2+ release from intracellular calcium pool.