Prolonged Copper Supplementation Modified Minerals in the Kidney, Liver and Blood, and Potentiated Oxidative Stress and Vasodilation of Isolated Aortic Rings in Young Wistar Rats.

BACKGROUND

Previous studies have highlighted that copper supplementation at 200% of the recommended daily dietary allowance modified vascular contraction and relaxation through increased reactive oxygen species (ROS) and prostaglandin formation, which modified the antioxidant status of middle-aged Wistar rats.

METHODS

In this study, young (1 month old) male Wistar rats (/group = 10) received a diet supplemented with 6.45 mg copper/kg (100% of daily recommendation-Group A) for 8 weeks. The experimental group received 12.9 mg copper/kg of diet (200% of the daily recommendation-Group B).

RESULTS

Experimental supplementation with 200% copper modified the copper concentration in the blood (1.21-fold, = 0.04), liver (1.15-fold, = 0.032), and kidneys (1.23-fold, = 0.045), potentiated the ROS formation in the aortic rings, and enhanced the sensitivity of the aortic rings to the vasodilator acetylcholine. We observed an increased participation of nitric oxide (NO) derived from inducible NO synthase (iNOS) in vascular contraction and a decreased net effect of vasodilator prostanoids derived from cyclooxygenase-2 in vascular relaxation. In rat kidneys, the concentrations of potassium (1.08-fold, = 0.001) and iron (1.13-fold, = 0.046) were higher, while, calcium (0.88-fold, = 0.001) and chromium (0.77-fold, = 0.005) concentrations were lower. In the rat liver, magnesium (1.06-fold, = 0.012) was higher. No differences were observed in the concentrations of sodium, zinc, manganese, selenium, cobalt, molybdenum, and vanadium. The antioxidant activity of water- and lipid-soluble compounds; total antioxidant status in the blood; and superoxide dismutase, catalase, and malondialdehyde levels in the heart did not change.

CONCLUSIONS

In young rats, prolonged supplementation with 200% copper had a lesser effect than anticipated on oxidative stress and vascular reactivity. Detailed data on the status of trace elements and their interactions in patients of different age groups are strongly required for effective nutritional and therapeutic intervention.