Renal ischaemia/reperfusion injury: possible role of aquaporins

Renal ischaemia/reperfusion (I/R) injury is a common problem that occurs when blood flow is interrupted to the kidney in case of kidney transplantation, aortic cross-clamping and shock with subsequent resuscitation. Renal I/R injury is a complex conditions which includes the onset of an inflammatory process, which is associated with impairment of concentrating ability of the kidney and impairment of solute transport. Characteristically, renal I/R injury is associated with marked reduction in the protein expression of renal aquaporins (AQPs) mainly (AQP1, AQP2 and AQP3), and solute transporters were observed in this condition and could account for the impaired urinary concentration that observed in this condition. Recently, many agents were tested for a possible protective effect against this insult such as erythropoietin (EPO), a-melanocyte-stimulating hormone (a-MSH) and a-lipoic acid which were proved to prevent downregulation of AQPs and solute transporters. The aim of this short review is to outline the potential pathophysiological role of AQPs in renal I/R injury and to put a spotlight on the modulation of renal functions impairment in renal ischaemia by new drugs that prevent downregulation of AQPs.