It can be concluded from this study that renal I/R resulted in deterioration of renal function, elevation of systolic blood pressure, elevation of p38 MAPK gene expression and peroxynitrite level in renal tissues. Estrogen provided a partially protective role against renal I/R injury as it produced an anti-oxidant and anti-inflammatory effects. L-NAME partially blocked this protective effect of estrogen suggesting that it may be mediated through NO. The anti-oxidant effect of estrogen was partially blocked by L-NAME denoting that it is mediated at least in part through NO. However, the anti-inflammatory action was not affected by L-NAME suggesting that it occurred through another mechanism.