摘要
Abstract
BACKGROUND: In bone tissue, the balance between bone formation and resorption is associated with the activities of hormones and growth factors in the whole body and local area. Limb immobilization increases bone resorption and decreases bone formation so that osteoporosis is induced. But a further recognition is expected on the relationship between growth factors and osteoporosis.OBJECTIVE: To observe the changes in concentrations of growth hormone (GH), insulin-like growth factor-Ⅰ (IGF-I) and somatostation in rat model with hind-limb immobilization.DESIGN: Randomized controlled observation was designed.MATERIALS: Totally 50 healthy SD male rates were employed, of clean grade, 6-month old and weighted varied from 290 to 320 g. They were randomized into immobilization group (n=40) and the control (n=10).METHODS: The experiment was performed in Department of Traumatic Surgery in the Hospital affiliated to Medical College of Qingdao University from February 2002 to January 2003. In immobilization group, the right hind-limb of rat was fixed with plaster on the abdomen and the rats were randomized into 4 groups, 10 rats in each, which were sacrificed after abdominal anesthetized on the 1st, 2nd, 4th and 8th weeks successively. The rats in the control group were sacrificed on the 8th week. Except that the immobilization was not applied in the control group, the other managements were same as immobilization group.MAIN OUTCOME MEASURES: Concentrations of GH, IGF-I and somatostation in the tissue extract in rat femurs in the control and on the 1st,2nd, 4th and 8th weeks after immobilization.RESULTS: All the 50 rats were all in result analysis. In immobilization group, GH level on the 8th week was increased remarkably than the control [(41.80±8.39), (19.86±4.21)μg/g, P ＜ 0.05], IGF-I in the femurs reached the peak on the 2nd week, which was higher remarkably than the control [(758.23±23.12), (499.60±18.76)μg/g, P ＜ 0.05], but on the 4th week, it was restored normal as the control and it was decreased remarkably on the 8th week [(258.65±5.76)μg/g, P ＜ 0.05]. Somatostation was higher significantly on the 8th week after immobilization compared with the control [(51.69±2.36), (34.63±8.85)μg/g, P ＜ 0.05].CONCLUSION: GH and IGF-I are not only relevant with bone formation,but also induce the increased concentration of peptides under enhanced bone resorption with immobilization, indicating the possible association with bone resorption.关键词
股骨/生长激素/胰岛素样生长因子Ⅰ/生长抑素分类
医药卫生
