Ischemic preconditioning protects post-ischemic renal function in anesthetized dogs: role of adenosine and adenine nucleotides

Aim: To investigate the effects of renal ischemic preconditioning (IPC) on both renal hemodynamics and the renal interstitial concentrations of adenosine and adenine nucleotides induced by ischemia-reperfusion injury. Methods: Renal hemodynamics responses to ischemia-reperfusion injury in mongrel dog models were determined with or without multiple brief renal ischemic preconditioning treatments, as well as the adenosine A, receptor antagonist (KW-3902), respectively. The renal interstitial concentrations of adenosine and adenine nucleotides in response to ischemia-reperfusion injury, either following 1-3 cycles of IPC or not, were measured simultaneously using microdialysis sampling technology. Results: One 10-min IPC, adenosine A, receptor antagonist (KW-3902) also shortened the recovery time of renal blood flow (RBF) and urine flow (UF), as well as mean blood pressure (BP). Advanced renal IPC attenuated the increment of adenosine and adenine nucleotides, as well as recovery time during the 60-min reperfusion which followed the 60-min renal ischemia. All of these recovery times were dependent on the cycles of 10-min IPC. The renal interstitial concentrations of adenosine and adenine nucleotides increased and decreased during renal ischemia and reperfusion, respectively. Conclusion: A significant relativity in dog models exists between the cycles of 10-min renal IPC and the recovery time of BP, UF, and RBF during the 60-min renal reperfusion following 60-min renal ischemia, respectively. Renal IPC can protect against ischemia-reperfusion injury and the predominant effect of endogenous adenosine induced by prolonged renal ischemia; renal adenosine A, receptor activation during the renal ischemia-reperfusion injury is detrimental to renal function.