Objective: To evaluate the effects of stanozolol on the bone mineral density (BMD) and bone biomechanical properties of rats with glucocorticoid (GC)-induced osteoporosis (OP).
Methods: Twenty-eight male Sprague-Dawley rats of 3-month old were randomly divided into Group A (the basal control group), Group B (the age-matched control group), Group C (GC-induced OP group) and Group D (stanozolol-administrated group), 7 in each group. The rats in Group A were killed when experiment commenced, and those in Group B were given normal saline ig., while those in Groups C and D received the prednisone acetate (4.5 mg/kg, twice a week) alone and in combination with stanozolol (0.5 mg/kg, 6 times a week), respectively. Ninety days later, the bilateral femur and the 5th lumbar vertebra of the rats were isolated for BMD test using dual-energy X-ray absorptiometry scanner, and the torsion test, three-point bending test and compression test using electronic testing device.
Results: Compared with Group B, the mean BMD of the femur and the 5th lumbar vertebra in Group C decreased by 14.64% (P<0.01), the BMD of the bilateral distal femoral segment and the 5th lumbar vertebra decreased by 21.42% (P<0.01), 19.62% (P<0.05) and 23.48% (P<0.01) respectively. The load that the femur withstood in three-point bending test decreased by 17.1% (P<0.05), and the other biomechanical parameters also declined. When compared with Group C, the BMD in Group D increased, the torsional angle of the femur increased by 72.5% (P<0.05) and the other biomechanical parameters also tended to increase.
Conclusions: BMD and biomechanical properties of the rat femur and the 5th lumbar vertebra decrease in response to a long-term GC administration, which can be prevented by stanozolol.