Effects of subchronic exposure to lead acetate and cadmium chloride on rat's bone: Ca and Pi contents, bone density, and histopathological evaluation.

Abstract

This study aims to investigate the effects of low-dose subchronic exposure to lead acetate (Pb(NO₃)₂) and cadmium chloride (CdCl₂·2.5H₂O) on bone in rats. The rats were assigned randomly to a control group and three experimental groups that were given the mixture of Pb(NO₃)₂ and CdCl₂·2.5H₂O by gastric gavage at doses of 0 mg/kg body weight (b.w.) (Group I, to serve as a control), 29.96 mg/kg b.w. (Group II, 29.25+0.71), 89.88 mg/kg b.w. (Group III, 87.74+2.14), and 269.65 mg/kg b.w. (Group IV, 263.23+6.42) for at least 90 consecutive days. Calcium (Ca) and phosphorus (Pi) contents in the bone were determined. Bone mineral density (BMD) was measured at the tibia and femur region by dual-energy X-ray absorbsiometry. The histopathology of bone was evaluated by light microscope, scanning electron microscope, and transmission electron microscope. The BMD of rats in the experimental group was significantly lower and the contents of Ca and Pi were decreased than those in the control group. The histopathological evaluation showed that co-induction of Pb and Cd results in bone microstructure damage, especially to trabecular bone, marrow cavity, collagen fiber, and osteoblast. In general, results indicate that combining Pb with Cd induces bone damage and increases the risk of osteoporosis.