| Objective To observe the effect of pioglitazone on PPARγ2, OCN, and BALP, and to explore the possible mechanism of pioglitazone and its relation to postmenopausal osteoporosis. Methods One hundred and forty-four healthy 3-month-old female Wistar rats were selected and divided into ovariectomized group and sham operation group. The rats groups were gavaged normal saline, 4mg/kg.d pioglitazone or 20 mg/kg.d pioglitazone. On different time point, RT-PCR was performed to determine the expression of PPAR γ2, enzyme linked immune assay was performed to detect the level of OCN and BALP, and DPX dual energy X-ray absorptiometry was used to detect the bone mass change of the experimental animals. Results 1) The expression of PPARγ2 showed a time-dependent increase after intervention with different doses of pioglitazone in two rat groups. OCN, BALP, and BMD showed a time-dependent decrease, and it was more significant in the ovariectomized group. The difference was statistically significant (P<0.05, P<0.01). 2) At the same time point, the expression of PPARγ2 showed a dose-dependent increase after intervention with different doses of pioglitazone in two rat groups. OCN, BALP, and BMD showed a dose-dependent decrease, and it was more obvious in the ovariectomized group. Statistical significance was found between the two groups (P<0.05，P<0.01). Conclusion Pioglitazone may up-regulated PPARγ2 expression by initiating its transcription activity. It reduces the expression of OCN and BALP, resulting in the occurrence of osteoporosis. |