Dietary vitamin C supplementation decreases blood pressure in DOCA-salt hypertensive male Sprague-Dawley rats and this is associated with increased liver oxidative stress.
The effects of a vitamin C supplemented diet on blood pressure, body and liver weights, liver antioxidant status, iron and copper levels were investigated in DOCA-salt treated and untreated Sprague-Dawley (SD) male rats after 8 weeks of treatment. Vitamin C supplementation had no effect on blood pressure in SD rats but induced a significant decrease in blood pressure in DOCA-salt treated rats, the decrease being more efficient at 50 mg/kg of vitamin C than at 500 mg/kg. Hepatic lipid peroxidation and iron levels were significantly increased in DOCA-salt hypertensive rats whereas total hepatic antioxidant capacity (HAC), glutathione peroxidase (GSH-Px) and catalase (CAT) activities were decreased. Vitamin C supplementation did not affect the overall antioxidant defences of control SD rat livers. In contrast, vitamin C supplementation accentuated the DOCA-salt induced accumulation of liver iron and lipid peroxidation. This occurred without any notable aggravation in the antioxidant deficiency of vitamin C supplemented DOCA-salt treated rat livers. Our data suggest that DOCA-salt treatment induces an accumulation of iron in rat livers which is responsible for the prooxidant effect of vitamin C. The normalization of blood pressure in DOCA-salt treated rats by vitamin C supplementation appears thus independent from liver antioxidant status.
Elhaïmeur
Fatiha
F
Laboratoire de Physiologie, UFR Médecine-Pharmacie, Besançon, France.
Courderot-Masuyer
Carol
C
Nicod
Laurence
L
Guyon
Catherine
C
Richert
Lysiane
L
Berthelot
Alain
A
D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000378:metabolism / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002374:Catalase / Q000378:metabolism; D003300:Copper / Q000378:metabolism; D003900:Desoxycorticosterone / Q000494:pharmacology*; D019587:Dietary Supplements; D016166:Free Radical Scavengers / Q000494:pharmacology; D005979:Glutathione Peroxidase / Q000378:metabolism; D006973:Hypertension / Q000378:metabolism* / Q000517:prevention & control* / Q000628:therapy; D007501:Iron / Q000378:metabolism; D008099:Liver / Q000378:metabolism / Q000473:pathology*; D008297:Male; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley
D000975:Antioxidants; D016166:Free Radical Scavengers; D003900:Desoxycorticosterone; D003300:Copper; D007501:Iron; D002374:Catalase; D005979:Glutathione Peroxidase; D001205:Ascorbic Acid