Effect of tempol, a synthetic antioxidant, on renal complications of L-NAME induced preeclampsia in rat

Introduction: It has been suggested that oxidative stress has a crucial role in the pathophysiology of preeclampsia. In the present study, the effect of tempol, a synthetic antioxidant, on kidney injuries and oxidative stress was investigated in an experimental model of preeclampsia in rats. Methods: Preeclampsia was induced by oral administration of L-NAME to the rats on the day 10 of pregnancy. Animals were randomly divided into six groups (10-15 rats in each group); (I) normal pregnant (II) preeclamptic (III, IV, V) preeclamptic + tempol 20, 60 and 180 mg/kg/day, respectively, (VI) preeclamptic + hydralazine 10 mg/kg/day. Urine levels of sodium, potassium, creatinine, lactate dehydrogenase and 24 h protein, blood levels of creatinine and urea, in addition to malondialdehyde concentration in blood and kidney, as well as histological glomeruli changes were assessed. Results: L-NAME administration caused proteinuria and glomerular pathological changes. Tempol (20 and 60 mg/kg/day) significantly reduced plasma and renal (P<0.001) malondialdehyde levels and proteinuria (the biggest calculated P-value was less than 0.05) in preeclamptic rats. Tempol at the dose of 20 mg/kg/day improved the histological changes in preeclamptic animals, but the dose of 60 mg/kg/day restored histological findings. L-NAME did not change the other measured parameters. Hydralazine and highest dose of tempol (180 mg/kg/day) failed to affect biochemical and histological changes in experimental preeclampsia. Conclusion: Renal complications of experimental preeclampsia such as proteinuria and glomerular injuries can be prevented by tempol. The desired effects of tempol depend on its dose.