Oxidative stress induced by chromium (VI) in bone of suckling rats.

摘要

Exposure to hexavalent chromium Cr(VI) compounds is of concern in many Cr-related industries and their surrounding environments. K(2)Cr(2)O(7) is widely recognized as an animal and human carcinogen, mutagen, and teratogen. The present study investigated the bone maturity of suckling rats whose mothers were treated with K(2)Cr(2)O(7). Experiments were carried out on female Wistar rats given 700 ppm of K(2)Cr(2)O(7) in their drinking water from the 14th day of pregnancy until day 14 after delivery. Exposing dams to K(2)Cr(2)O(7) caused disorders in the bone of their progeny. As corollary to this, malondialdehyde levels increased, while glutathione, a non-protein thiol and vitamin C decreased. Alteration of the antioxidant system in the treated group was also confirmed by the significant decline of superoxide dismutase, catalase, and glutathione peroxidase activities. Furthermore, K(2)Cr(2)O(7) induced changes in bone mineralization, especially calcium and phosphorus levels, which decreased. Whereas, in plasma and urine, they increased and decreased inversely. These results suggest that K(2)Cr(2)O(7) accelerated bone resorption activity. In fact, in treated pups, total tartrate-resistant acid phosphatase, which reflected bone resorption, was enhanced while total alkaline phosphatase, which reflected bone formation, was reduced. The impairment of bone function was corresponded histologically.