Abstract： BACKGROUND: Interleukin-6 (IL-6), osteocalcin (OC) and bone alkaline phosphatase (BALP) are involved in bone metabolism, which is correlative with osteoporosis.OBJECTIVE: To observe expression properties of IL-6, OC and BALP in rats with osteoporosis.DESIGN: Control experiment with observation of randomized group division was designed.SETTING: Orthopedics Department of Shenzhen People's Hospital (2nd Affiliated Hospital of Medical College of Jinan University)MATERIALS: The experiment was performed in Animal Laboratory Room and Center Laboratory Room of Shenzhen People's Hospital from January 2002 to January 2003, in which, 60 SD female rats of 6 months were employed, averagely weighted 250 g. They were randomized into 3 groups, named ovariectomized (OVT) group, control and blank group, 20 rats in each.METHODS: In OVT group, the ovaries of rat were removed bilaterally to establish osteoporosis model. In the control, after the ovary was lifted out of abdominal cavity when the abdomen was opened, it was returned back and the abdomen was closed. In blank group, no any management was performed. In 2, 3, 4, 5 and 6 months after surgery, 4 rats were randomized from each group for assays of bone density, OC, IL-6 and BALP.MAIN OUTCOME MEASURES: Changes of bone density, OC, IL-6 and BALP of whole body of rat.assay in rats: In 4, 5 and 6 months, in OVT group, bone density was reduced remarkably compared with the control and blank group [in 4 months:(0.139 5±0.007 8), (0.147 0±0.000 8), (0.145 9±0.002 9) g/cm2; in 5 months: (0.137 9±0.000 9), (0.145 6±0.000 8), (0.144 7±0.000 5) g/cm2; in 6 months: (0.122 6±0.000 4), (0.145 0±0.002 1), (0.144 0±0.000 9) g/cm2, P sults of IL-6 assay in rats: At every time spots, IL-6 in OVT group was sults of BALP in serum of rats: In 4, 5 and 6 months, BALP in OVT group was higher significantly than the control and blank group [(2 026±4) vs (1 247±12), (1 291±7) nkat/L, (2 342±9) vs (1 273±18), (1 342±12) nkat/L,(2 633±15) vs (1 340±9), (1 357±8) nkat/L, P ＜ 0.05].CONCLUSION: In the rats with osteoporosis, bone density is decreased significantly and IL-6, OC and BALP are significantly expressed, which can be taken as the indexes for diagnosis and screen of osteoporosis.Zhang XM, Xu ZS, Xiao DM, Li R.Expression properties of interteukin-6, osteocalcin and bone alkaline phosphatase in osteoporosis rats Zhongguo Linchuang Kangfu 2005;9(43):190-2(China) [www.zglckf.com]INTRODUCTIONOsteoporosis induces complications, like bone fracture, which is associated with various factors, such as estrogen level. Osteocalcin (OC) is a kind of active multi-peptide secreted from osteoblasts,which plays the importance in regulating calcium metabolism and is a new biochemical mark in study on bone metabolism. Interleukin-6 (IL-6) provides powerful bone absorption and stimulation,which plays the important role in coupled information exchange ofbone absorption and formation. In this experiment, ovarietomy was done bilaterally in SD female rats to establish osteoporosis, afterwards, bone density, serum OC, IL-6 and bone alkaline phosphatase (BALP) were determined to probe into their relationship with the incidence of osteoporosis.