The Effect Of Alendronate On The Expression Of Osteoprotegerin In Rats Calcified Aorta Tissue

Objective: To study the effect of Alendronate on the expreesion of osteoprotegerin(OPG)in rat aorta, and investigate the possible mechanism of inhibiting artery calcification by Alendronate.Methods: Twenty-seven 4-week-old male SD rats (200-250g) were randomly divided into 3 groups: the control group (n=7), calcification group(n=10) and alendronate group (n=10). The later two groups were subcutaneously injected with warfarin (15mg/ 100g per 12 hours for 5 days) and vitD3 (3×105U/kg per day for 3 days) to induce extensive calcification of the aorta. Alentronate group was treated with daily subcutaneous injection of alendronate beginning 4 days before the first warfarin dose. The control group was given daily subcutaneous injection of 0.9%Nacl. Thoracic aortas were excised for analysis of calcification and OPG expression using histomorphometry, spectrophotome RT-PCR and immunohistochemistry.Results: The large area of focal darkly stained regions by Von kossa staining reduced obviously in alendronate group. The level of calcium content in aorta wall was significantly lower in the alendronate group[(67.33±19.86)μmol/g] than in the calcification group[(114.3±23.23)μmol/g] (p<0.05). The relative content of OPG mRNA in aortic wall was higher in the alendronate group than in the calcification group(P<0.01). The similar results is drawn by immuohistochemistry. OPG protein expression was similar to that seen for its mRNA expression.Conclusions: Alendronate inhibited artery calcification by upregulating the expression of OPG.