Establishment of an osteoporosis model in tree shrews by bilateral ovariectomy / 中国实验动物学报

ABSTRACT

Objective To establish an osteoporosis model in tree shrews by bilateral ovariectomy.Methods One hundred healthy 6-24 month old female tree shrews were used in this study.The diagnosis and treatment of osteoporo-sis in the model tree shrews was assessed according to the Interpretation of the Clinical Practice Guideines for Primary Oste-oporosis 2011 released by the Chinese Medical Association of Osteoporosis and Bone Mineral Salt Disease Branch.① Ac-cording to the human natural life span, sexual maturation time and peak bone mineral density ( PBMD) and the tree shrew natural life span and sexual maturation time, we estimated the PBMD of tree shrew in the age of months.Six 6-, 12-, 18-and 24-month old tree shrews in each group were randomly taken for measurement of BMD, and compared the differences between groups to verify the PBMD age of tree shrews.②We chose 62 6-month old tree shrews from the rest of tree shrews to measure their BMD to determine the mean and standard deviation of BMD.Then we divided them into study group ( n =32) and control group (n =30).Bilateral ovariectomy was performed in the study group, while omentectomy was done in the control group.BMD was measured at 3, 6, 9, 12 months after the surgery, 6 animals from each group.The animals which met the criteria of guideline were taken for pathological examination.Results ①The PBMD of 6-, 12-, 18-, 24-month old tree shrews was 0.138 ±0.012, 0.143 ±0.010, 0.141 ±0.009, and 0.139 ±0.009) g/cm2 , respectively, showing no significant differences among them (P>0.05).②The mean PBMD of the tree shrews was 0.143 ±0.016 g/cm2 .③In the model groups, the number of tree shrews whose BMD met the criteria of guideline was 0, 5, 4, 5, respec-tively.The pathological examination of the proximal tibia from the model group showed sparse and some disrupted trabecu-lae and enlarged inter-trabecular space.In the control group, the tibia tissues showed normal histology of bone structure and no one tree shrew showed a BMD value which met the criteria of diagnosis of osteoporosis.Conclusions An osteopo-rosis model in tree shrews can be established at 6 months after bilateral ovariectomy, showing similar manifestation of osteo-porosis in postmenopausal women.The success rate of this modeling method is high and the model is stable.