Aleo M F, Sestini S, Pompucci G, Preti A
Department of Biomedical Sciences and Biotechnology, University of Brescia, Italy.
J Cell Physiol. 1996 Apr;167(1):173-6. doi: 10.1002/(SICI)1097-4652(199604)167:1<173::AID-JCP20>3.0.CO;2-B.
The fate of nicotinamide adenine dinucleotide (NAD), AMP, and ADP-ribose supplied to intact human skin fibroblasts was monitored, and the concentrations of intra- and extracellular pyridine and purine compounds were determined by HPLC analysis. Two enzymatic activities affecting extracellular NAD were detected on the plasma membrane, one hydrolyzing the pyrophosphoric bond and yielding nicotinamide mononucleotide (nucleotide pyrophosphatase) and the other cleaving the glycoside link and releasing nicotinamide (NAD-glycohydrolase). No AMP or ADP-ribose was found in the extracellular medium of cells incubated with NAD, the former being completely catabolized to hypoxanthine and the latter degraded to adenine and hypoxanthine.
监测了供应给完整人皮肤成纤维细胞的烟酰胺腺嘌呤二核苷酸（NAD）、AMP和ADP - 核糖的命运，并通过高效液相色谱分析测定了细胞内和细胞外吡啶和嘌呤化合物的浓度。在质膜上检测到两种影响细胞外NAD的酶活性，一种水解焦磷酸键生成烟酰胺单核苷酸（核苷酸焦磷酸酶），另一种裂解糖苷键释放烟酰胺（NAD - 糖水解酶）。在用NAD孵育的细胞的细胞外培养基中未发现AMP或ADP - 核糖，前者完全分解代谢为次黄嘌呤，后者降解为腺嘌呤和次黄嘌呤。
