Effect of alfacalcidol on bone regeneration in senile rats

Background. Among the drugs that have a pleiotropic effect on bone, attention is drawn to alfacalcidol - the precursor of the active form of D-hormone. There are studies that have revealed distinctive features of the effect of alfacalcidol on bone regeneration in osteoporosis and in young animals. The purpose was to study bone regeneration after treatment with alfacalcidol in senile animals. Materials and methods. A transcortical defect from the lateral to the medial femur was modeled in rats aged 24 months in the area of the metadiaphysis. A treatment with alfacalcidol was carried out from the 2-nd day and for 10 and 30 days before the animals was withdrawn from the experiment. Histological study of bone regeneration with morphometric analysis of tissues in the areas of callus had been performed. Results. On the 10-th day of the treatment with alfacalcidol in senile animals, connective tissue, osteoid and coarse-fibrous trabecular bone with a high density of osteoblasts were located in the defect area. On the 30-th day in treated animals, the bone tissue of the callus was mature; its area was larger than in untreated animals. In the area of cancellous bone there is a network of newly formed bone trabeculae. Destructive manifestations around the defect were reduced in animals treated with alfacalcidol. In untreated animals there was no dense bone fusion with cortex fragments; trabeculae of cancellous bone were intermittent. In the lateral part of the callus, the area of bone tissue was reduced compared to the medial part. Conclusions. Treatment of animals with alfacalcidol accelerates the formation of bone tissue in the defect and reduces destructive manifestations around the defect compared to untreated animals.