Pathophysiology of A1 Adenosine Receptor Inhibition in Acute Kidney Injury Induced by Ischemia-Reperfusion: a Review Study

Background & objectives: One of the most important causes of acute kidney injury is ischemia-reperfusion (IR). Some studies have shown that adenosine A1 receptor inhibition have protective effects against Ischemia–reperfusion induced renal injuries, while other studies have demonstrated the opposite. The aim of the present study was to review the methodology of these studies to reach a final conclusion about the effects of adenosine A1 receptor on ischemia-reperfusion-induced renal injuries. Methods: Data base motors including Scopus, PubMed, Google Scholar, Science Direct and Embase were searched. The terms and keywords used included ischemia-reperfusion, acute kidney injury, acute renal failure, A1 adenosine receptor and their combination. Results: Increased adenosine levels following renal Ischemia-reperfusion cause vasoconstriction in afferent arteriole and vasodilatation in efferent arteriole through A1 adenosine receptor activation, which in turn reduces glomerular filtration rate (GFR). Inhibition of A1 adenosine receptor leads to short-term correction of renal functional parameters following renal Ischemia-reperfusion, by increasing renal blood flow and thus improving GFR. But this increase in GFR exacerbates kidney damages through the kidneys workload enhancement, which will show up in the next few hours. Conclusions: Although selective inhibition of A1 adenosine receptor in the short term improves renal function parameters, but exacerbates renal damages in the following hours. Therefore, adenosine A1 receptor stimulation has protective effects against IR-induced kidney injury.