A Study on the Effect of Sildenafil Citrate on Acute Renal Ischemic-Reperfusion Injury in Male Rats

Several studies suggest that acute ischemia reperfusion (IR) of the kidney results in deterioration of its performance resulting in bad outcome of kidney transplantation operations and major operations in which the kidneys are exposed to acute ischemia reperfusion. The present study was designed to investigate if sildenafil citrate (SC) has a protective role in renal I/R injury and to study its possible mechanisms of action in rats by inducing bilateral renal ischemia followed by one hour reperfusion and measurement of serum creatinine, blood urea nitrogen and nitric oxide (NO) level in renal tissues. 60 rats were used & were subjected to sham operated (control group-1), 50min renal ischemia (group-2), ischemia for 50 minutes then reperfusion for 2 hours (group-3), SC (1mg/kg orally) + sham operated group (group-4). Ischemia of the kidneys for 50 minutes, one hour after SC oral treatment (Group 5), I/R of the kidneys, one hour after SC oral treatment (Group 6). Results: The study documented that I/R resulted in a significant increase (p<0.05) in the serum creatinine, blood urea nitrogen levels, rat tail systolic blood pressure and a significant decrease (p<0.05) in NO level in renal tissues. SC prophylactic treatment resulted in partial reversal of measured parameters compared to the groups untreated with the same drug. There was a significant decrease ( p<0.05) in serum creatinine, blood urea nitrogen and a significant increase (p<0.05) in NO level in renal tissues in I/R after SC prophylactic treatment compared to the groups untreated with the same drug. It can be concluded from this study that renal I/R resulted in deterioration of renal function, elevation of systolic blood pressure and decreased NO level in renal tissues. SC provided a partially protective role against renal I/R injury as after prophylactic treatment with SC kidney functions were ameliorated and the level of NO in kidney tissue increased suggesting that this protective effect of SC may be mediated through NO. However, there was no significant difference in rat tail systolic blood pressure after SC prophylactic treatment suggesting that this drug has no significant secondary systemic effects. Correspondence to: Dr. Hassan M. Eissa, The Department of Medical Physiology, Faculty of Medicine, Cairo University