Effects Of PM2.5 Suspension On Bone Density Of Pre-menopause And Post-menopause SD Rats

Objective:Postmenopausal osteoporosis(PMOP)is a common type of primary osteoporosis,which is a common and frequent disease in postmenopausal women.Mainly due to women’s postmenopausal ovarian dysfunction and estrogen levels decreased significantly,resulting in metabolic imbalance of bone formation and bone resorption,prone to fractures and other complications.In recent years,foreign studies have suggested that the environment can be used as a factor affecting osteoporosis,but there are few reports on whether the environment is related to postmenopausal osteoporosis.In this experiment,the bone density and serum bone metabolism markers BALP,CTX,PINP,PICP,OC,PYR,D-PYR,TRACP-5b of SD female rat osteoporosis model before and after ovarian ovariectomy were observed by different concentrations of PM2.5 exposure Level of influence.Preliminary discussion of different levels of PM2.5 exposure may be related to the severity of PMOP.Methods:360 female SPF grade SD rats of 3W age were randomly divided into four groups:control group,low-dose group,medium-dose group,and high-dose group,with 90 rats in each group.Each group was infused with PM2.5 suspension(From Fuzhou area)at the corresponding concentration every 3 days for 5 months.At the end of 5 months,each group was randomly divided into surgery group and sham operation group,with 45 animals in each group.The ovary was removed in the operation group,and the ovarian fat tissue was removed in the sham operation group.The experimental perfusion was continued for 4 months after the operation,and the rats were sacrificed at the end of 9 months after airway perfusion.At the end of March,the end of May,the end of July,and the end of September,3 days before the measurement of bone density,the venous blood of the canthus was taken for ELISA kit to detect the bone metabolism markers BALP,CTX,PINP,PICP,The content of OC,PYR,D-PYR and TRACP-5b.At the end of March,May,July,September and the removal of isolated bone from the airway,Dual energy X-ray instrument(DXA)was used to measure the bone density of the right tibia,right femur and lumbar vertebrae L4～L6 of each rat.Results: Serum BALP,CTX,OC,PYR,D-PYR:At the end of airway infusion at the end of May,July,and September,the middle-dose group and the high-dose group in the surgery group and sham operation group were significantly compared with the control group.Increased(P<0.05).Serum PICP:At the end of May,the end of the seventh month,and the end of September,the middle-dose group and the high-dose group in the sham operation group were significantly increased compared with the control group(P<0.05);PINP in the serum:Airway instillation at the end of May,the end of the seventh month,and the end of September,the middle-dose group and the high-dose group in the surgery group were significantly increased compared with the control group(P<0.05);serum TRACP-5b:sham operation group,There was no statistically significant difference in the serum TRACP-5b value among the four dose groups within the operation group at four time points(P>0.05).Tibia bone density:At the end of May,July,September and airway infusion,the medium and high dose groups in the surgery group and the sham operation group were lower than the control group(P<0.05),the difference in bone density value has statistical significane.Femoral bone density:At the end of May,July,September and airway infusion,the medium and high dose groups in the surgery group and the sham operation group were lower than the control group(P<0.05).Statistical significance.Bone density of lumbar vertebrae L4～L6:At the end of May,July,September and airway infusion,the medium and high dose groups in the surgery group and the sham operation group were lower than the control group(P<0.05),bone The difference in density values is statistically significant.Conclusion: 1.Different dose groups of PM2.5 can reduce the bone density of premenopausal and postmenopausal female SD rats(P<0.05),and accelerate the degree of postmenopausal osteoporosis.2.Different dose groups of PM2.5 will increase the levels of some bone metabolism indexes in the serum of premenopausal and postmenopausal female SD rats(P<0.05).