Miller W L, Thomas R A, Berne R M, Rubio R
Circ Res. 1978 Sep;43(3):390-7. doi: 10.1161/01.res.43.3.390.
We conducted experiments to determine (1) tissue, blood, and urine levels of adenosine produced by the ischemic kidney under conditions of renal artery occlusion, and (2) the site(s) of production and release of adenosine by the kidney. Concentrations of adenosine, inosine, and hypoxanthine in the dog urine were found to increase after 2 minutes of renal artery occlusion as were concentrations of these metabolites in renal tissue after 10 minutes of renal artery occlusion. Renal venous plasma levels of inosine and hypoxanthine also were elevated after 3 minutes of arterial occlusion. In modified stop-flow experiments, adenosine appeared in the urine in a peak that corresponded most closely with proximal tubule fluid. 5'-Nucleotidase, the enzyme which catalyzes the dephosphorylation of 5'-AMP or 5'-IMP to adenosine or inosine, respectively, was found to be located primarily on the external membranes and mitochondria of proximal tubule cells, but not in distal tubule or collecting duct cells. Since adenosine has been demonstrated to elicit renal vasoconstriction and is produced by the ischemic kidney, it is suggested that adenosine may be involved in the mediation of postocclusion renal ischemia.
（1）在肾动脉闭塞情况下，缺血肾脏产生的腺苷在组织、血液和尿液中的水平；（2）肾脏产生和释放腺苷的部位。发现肾动脉闭塞2分钟后，犬尿液中腺苷、肌苷和次黄嘌呤的浓度增加，肾动脉闭塞10分钟后，这些代谢产物在肾组织中的浓度也增加。动脉闭塞3分钟后，肾静脉血浆中肌苷和次黄嘌呤的水平也升高。在改良的停流实验中，腺苷出现在尿液中的峰值与近端小管液最为吻合。5'-核苷酸酶，即分别催化5'-AMP或5'-IMP脱磷酸生成腺苷或肌苷的酶，主要位于近端小管细胞的外膜和线粒体上，而在远端小管或集合管细胞中未发现。由于腺苷已被证明可引起肾血管收缩且由缺血肾脏产生，因此提示腺苷可能参与了闭塞后肾缺血的介导过程。
