Tehran University Medical Journal

Background: Obstructive nephropathy has been associated with disorders in metabolism state and oxidative balance of kidney. Stress oxidative play a key role in the pathophysiological processes of renal diseases. The objective of this study was to investigate effects of vitamin-E, as a powerful antioxidant, on renal oxidative stress and metabolism defect induced by 24-hr unilateral ureteral obstruction (UUO).

Methods: Anesthetized male Sprague-Dawley rats (n=10 in each group) were sterilely operated to occlude the left ureter. In UUO+NS, we had a single dose normal saline injection and in UUO+VitE and UUO+OO groups, D-α-tocopherol (50 mg/kg), the main component of vitamin-E, and its vehicle (Olive Oil), respectively, were twicely infused I.P. before and after UUO-induction. There were also sham-operated and control groups. 24-hr after of UUO-induction, both kidneys were removed and stored in -70°C. To determine metabolism condition, the levels of ATP and ADP and to evaluate redox state, the levels of malondialdehyde (MDA) and ferric reducing/antioxidant power (FRAP) of kidneys were assessed.

Results: The comparisons between UUO+NS and sham groups indicated that UUO increased MDA (p<0.001) and ADP (p<0.05), but decreased FRAP, and ATP/ADP ratio in obstructed kidney (all p<0.001). In UUO+VitE group, MDA and FRAP were equal to their levels in sham group, while ATP, ADP and ATP/ADP ratio were not different from those of UUO+NS group in obstructed kidney.

Conclusion: Twenty four hour of UUO caused renal reduction in oxidative metabolism and elevations in reactive oxygen species and administration of vitamin-E, although considerably ameliorated the oxidative stress, could not improve the defected metabolism.