THE ROLE OF CALCIUM IN THE MODULATION OF THE HEPATIC ANTIOXIDANT DEFENSE SYSTEM

A normocalcemic animal model of vitamin D (vit. D) - deficiency has been successfully developed by feeding a high calcium (Ca2+) diet to vit. D. - deficient rats. The modulating role of Ca2+ on the hepatic antioxidant defence system and lipid peroxidation has been evaluated in this model. Partial restoration of liver function was noted in these rats following extra Ca2+ feeding. Serum alkaline phosphatase and alanine aminotransferase reverted to a normal level. The reduced levels of hepatic SOD and glutathione peroxidase in vit. D. - deficient rats, were also increased after extra Ca2+ supplementation. Even elevated lipid peroxidation due to vit. D. - deficiency was reduced after feeding the extra Ca2+-supplemented diet. However, catalase activity remained at the control level throughout the study. The results provide important evidence that normocalcemia is essential for maintaining the he tic antioxidant defence and controlling lipid peroxidation in the in vivo milieu.