Increased nitration and diminished activity of copper/zinc superoxide dismutase in placentas from diabetic rats.

WHITE VERÓNICA; CAPOBIANCO EVANGELINA; HIGA ROMINA; MARTÍNEZ NORA; SOSA MARÍA; PUSTOVRH MARÍA CAROLINA; JAWERBAUM ALICIA

FREE RADICAL RESEARCH

TAYLOR & FRANCIS LTD

Año: 2010 vol. 44 p. 1407 - 1415

1071-5762

Nitration-induced protein damage in the placenta leads to impaired blood fl ow and deficient feto–placental exchange in diabetic pregnancies. This work studied the effect of nitric oxide and peroxynitrite on Cu/Zn SOD activity in rat placentas and evaluated whether Cu/Zn SOD is nitrated in the placenta from diabetic rats at mid-gestation. Protein nitration was evaluated by EIA, Cu/Zn  SOD activity by inhibition of the epinephrine auto-oxidation, Cu/Zn SOD expression by western blot and specifi c nitration by immunoprecipitation. This study found higher levels of protein nitration ( p<0.001), diminished Cu/Zn SOD activity and enhanced protein expression ( p<0.01) in placentas from diabetic rats. Placental Cu/Zn SOD activity was inhibited by peroxynitrite (p<0.01). Besides, nitration of Cu/Zn SOD was elevated in placentas from diabetic rats ( p<0.01). These results show that rat Cu/Zn SOD can be nitrated, a modifi cation that could lead to the depressed activity of this enzyme found in placentas from diabetic rats.