Stepiński J, Bizon D, Piec G, Angielski S
Department of Clinical Biochemistry, Medical Academy, Gdańsk, Poland.
Am J Kidney Dis. 1989 Oct;14(4):307-9. doi: 10.1016/s0272-6386(89)80209-4.
Formation of adenine nucleotides, IMP, malate + fumarate, ammonia, adenosine, and inosine + hypoxanthine + uric acid were measured in cytosolic extracts from renal cortex and medulla. The order of substrate addition was IMP, then 2-deoxyglucose, then P-creatine. Compared with cortex, medulla showed greater rates of formation of adenosine triphosphate (ATP) from P-creatine, of adenosine monophosphate (AMP) from 2-deoxyglucose, and of total adenine nucleotides from IMP. These results suggest that the purine nucleotide cycle is more active in medulla than in cortex. This cycle may provide a mechanism in medulla for storing purine nucleotides which can be used to restore ATP pools in the relatively hypoxic conditions of this part of the kidney.
在肾皮质和髓质的胞质提取物中测量了腺嘌呤核苷酸、肌苷一磷酸（IMP）、苹果酸+富马酸、氨、腺苷以及肌苷+次黄嘌呤+尿酸的生成情况。底物添加顺序为IMP，然后是2-脱氧葡萄糖，接着是磷酸肌酸。与皮质相比，髓质从磷酸肌酸生成三磷酸腺苷（ATP）、从2-脱氧葡萄糖生成单磷酸腺苷（AMP）以及从IMP生成总腺嘌呤核苷酸的速率更高。这些结果表明嘌呤核苷酸循环在髓质中比在皮质中更活跃。该循环可能为髓质提供一种机制，用于储存嘌呤核苷酸，这些嘌呤核苷酸可用于在肾脏这一部分相对缺氧的条件下恢复ATP池。
