| Objective: To investigate the therapeutic effect and explore the biomoleculogic mechanism of the bionics pulsed electromagnetic fields in postmenopausal osteoporosis.Methods: Forty 6-month old female Wistar rats were randomly divided into four different groups: ovariectomy group(OVX),sham operation group (Sham), E group (Estrogen+OVX E) and EM group(BEMF+OVX EM). All rats were subjected to bilateral ovariectomy except the sham operation group. After 8 weeks operation, E group rats were given estrogen 0.5mg/kg/1,1/2W. EM group rats were exposed to bionics electromagnetic fields (BEMF) ,lh /d. OVX and Sham group rats were given nothing as the controlled groups.All the treatments were bing kept for 10 weeks. After the treatments finished, meauring the markers as follow: the general condition(the body mass, uterus mass, amount of uterus glands) and the bone mineral density(BMD)( femur and lumbar vertebrae), the biomechanical property ,femur dry mass, the calcium content of femur. Bone morphology were observed by light microscope (proximal tibial metaphyseal trabecular bone)and scan electric microscope(lumbar vertebrae).The histomorphometric analyses were also done to left tibia. At the same time, biochemical markers (serum and urine) were determined.The cells apoptosis condition(osteoblast,osteoclast and osteocyte) in lumbar vertebrae were observed by transmission electric microscope and with TUNEL technic.At the same time,the expression of apoptosis controlling gene Fas,bax,bcl-2 protein were determined by immunochemistry. The osteoblast, osteoclast were also counted with histomorphometric analyse. The expression of TGF , bFGF, IL-6 mRNA and protein were examinated with in situ hybrization and immunochemistry.Results:After the treatment with BEMF, BMD significantly increased by 24.3% at the lumbar spine and by 12.1% at the femur (vs. OVX).The BMD of lumbar spine was significantly increased by 27.9% and by 8.8% at the femur (vs. OVX) in E group.There were significant differences between E group and OVX group, EM group and OVX group(P<0.05),but there were no significant differences between E group and EM group.Compared with OVX group, the biomechanical property(maximum loads) of EM group markedly significantly increased by 22% at the lumbar spine and by 13.3% at the femur (vs. OVX). The E group biomechanical property(maximum loads) of lumbar spine was significantly increased by 13.6% and by 8.3% at the femur (vs. OVX).BEMF stimulation augmented and restored proximal tibial metaphyseal trabecular bone mass (bone volume percentage %Tb.Ar, and trabecular number Tb.N ) and architecture (increased trabecular thickness Tb.Th, and decreased trabecular separation Tb.Sp) .No matter E group or EM group, %Tb.Ar, Tb.Th, Tb.N were significantly higher than OVX group,there were significantly difference vs. OVX group(P<0.05).On the other hand, Tb.Sp significantly lower than OVX group, there were significantly difference(P<0.05).Light microscope and scan electric microscope observation showed trabecular volume and trabecular connections significantly increased in E and EM group than in OVX.BEMF stimulation exposure attenuated the serum TRAP concentrations of OVX rats and restored it to levels of Sham rats. BEMF stimulation exposure elevated serum BGP and ALP concentrations of OVX rats. BEMF stimulation exposure attenuated urine calcium and phosphor.Observation of transmission electric microscope and TUNEL examination showed that BEMF stimulation exposure attenuated the apoptosis of osteoblast and osteocyte, elevated the apoptosis of osteoclast. Histomorphometric analyse showed that BEMF stimulation exposure decreased osteoclast and osteoblast amount significantly.The Fas,bax,bcl-2 protein examination showed that theBEMF stimulation exposure significantly attenuated Fas and bax expression in osteoblast and osteocyte,on the other hand, bc1-2 protein expression increased. The BEMF stimulation exposure significantly increased Fas and bax protein expression in osteoclast,on the other hand, bcl-2 protein expression signi...
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