Background: Glucocorticoids are widely used in the clinical setting. The direct impacts of glucocorticoids on bones involve both transient and early rise in bone resorption and long-term inhibition of bone formation. Leptin enhances the differentiation of human bone marrow stromal cells into osteoblasts, suppresses the generation of osteoclasts and attenuates the reduction in bone formation.
Objectives: This study aimed to assess the effects of prednisolone on causing osteoporosis in rats and the effects of leptin on osteoporotic rats.
Material and Methods: The study was performed on 21 adult male white albino rats. They were divided equally into; control, osteoporotic and treated groups. The osteoporotic and treated groups were given 5 mg/kg/day oral prednisolone for 3 months. The treated group was given10 μg/kg/day intraperitoneal (IP) leptin for the next 2 months. Blood samples were collected for determination of serum calcium, phosphorous, alkaline phosphatase and osteocalcin levels. Bone of the right femur was used for histopathological examination.
Results: The osteoporotic group had a highly significant decrease in serum calcium and phosphorus, in addition to significant increase serum alkaline phosphatase and osteocalcin. Also, there was decrease in cortical bone thickness and number of osteocyte-containing lacunae and increased number of osteocyte-free lacunae in osteoporotic group. Treatment with leptin improved both biochemical and structural changes in prednisolone induced osteoporosis.
Conclusions: Leptin antagonizes the effects of glucocorticiods induced osteoporosis. It normalizes serum calcium and phosphorus. It improves bone mineral density and bone size.