环化二磷酸腺苷核糖及其钙动员的功能

Cyclic ADP-Ribose and its Calcium Mobilizing Function

环化二磷酸腺苷核糖（ｃｙｃｌｉＡＤＰ－ｒｉｂｏｓｅ，ｃＡＤＰＲ）是烟酰胺腺嘌呤二核苷酸（ＮＡＤ＋）的代谢产物，是新近发现的一种细胞内第二信使．在许多哺乳类和无脊椎动物细胞中，ｃＡＤＰＲ能引起胞内钙库释放钙离子，其可能机制是：ｃＡＤＰＲ受体结合ｃＡＤＰＲ，通过Ｒｙａｎｅｄｉｎｅ受体或类Ｒｙａｎｏｄｉｎｅ受体介导的钙通道使ｃＡＤＰＲ敏感的钙库释放钙离子，此外，一条由一氧化氮（ＮＯ）、环化鸟苷酸（ｃＧＭＰ）和ｃＡＤＰＲ组成的细胞内信号转导途径可能存在于许多细胞中．

Cyclic ADP-ribose (cADPR) is a novel endogenous metabolite of nicotinamide adenine dinucleotide (NAD+), and is a recently discovered second messenger. cADPR is active in mobilizing intracellular Ca2+ in invertebrate as well as mammalian cells. The mechanism of releasing Ca2+ from internal pool (s) has been studied. cADPR may bind its receptor, which in turn induces the release of Ca2+ from cADPRsensitive Ca2+ pool(s) through ryanodine receptor or ryanodine receptor-like mediated Ca2+ channel. In addition, a possible intracellular signal transduction pathway involving nitric oxide (NO), cyclic guanylic acid (cGMP) and cADPR has been suggested to exist in various cells.