Ovariectomy induces oxidative stress and impairs bone antioxidant system in adult rats.

Abstract

BACKGROUND: There is increasing evidence suggesting the role of free radicals in bone resorption and bone loss. Ovariectomized rats have been used as the animal model for the study of osteoporosis. Oxidative stress due to reactive oxygen species (ROS) can cause oxidative damage to cells. Cells have a number of defense mechanisms to protect themselves from the toxicity of ROS. Even though, there are studies portraying the role of free radicals in bone loss, the defense mechanism adapted by bone in ovariectomized animals remains obscure. We investigated the impact of ovariectomy (OVX) on the bone antioxidant system in rats. METHODS: Sixty days after bilateral OVX, the rats were killed and the femora were removed, the tissue homogenates were made and used for the estimation of superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S transferase (GST), lipid peroxidation (LPO) and hydrogen peroxide (H(2)O(2)). RESULTS: The levels of LPO and H(2)O(2) were increased and enzymatic antioxidants like SOD, GPx, GST were decreased in ovariectomized animals when compared to sham-operated control rats. The calculated correlation coefficient demonstrated strong correlation (0.905) between the production of H(2)O(2) and LPO in the femur bone. A strong inverse (-0.945) correlation was observed between H(2)O(2) production and SOD activity. CONCLUSIONS: OVX induces oxidative stress in the femur bone of rats.