[Skeletal biomechanical effectiveness of retinoic acid on induction of osteoporotic rats treated by alendronate and qianggu capsules]

To study the effectiveness of retinoic acid on induction of osteoporotic rats treated by either alendronate or qianggu capsules and co-administration.Sixty-five female SD rats were treated with retinoic acid 80 mg x kg(-1) x d(-1) by gastric lavage for 15 days. Then 5 rats were confirmed cases of osteoporosis and the remaining 60 were randomly divided into 4 groups 15 each: (1) control group with NS 8 ml x kg(-1) x w(-1); (2) alendronate group with alendronate 40 mg x kg(-1) x w(-1); (3) qianggu group with qianggu capsules 90 mg x kg(-1) x d(-1); (4) co-medicated group with alendronate 40 mg x kg(-1) x w(-1) and qianggu capsules 90 mg x kg(-1) x d(-1). Five rats in each group were sacrificed at week 2, 4 and 6 respectively to carry out the biomechanic tests, histopathologic examination and bony callus volume calculation.Biomechanical properties of femur changed significantly after the treatment by alendronate or qianggu capsules and co-medication as compared with that of NS after 4 weeks (P0.05); the bony callus were larger when treated by alendronate (P0.05) and smaller by qianggu capsules (P0.05); the bone trabecula formed and rebuilding were slower by alendronate and quicker by qianggu capsules.Alendronate or qianggu capsules and co-medication can improve biomechanical properties of femur by retinoic acid on induction of osteoporotic rats. Qianggu capsules can improve bone union.