运动对去势大鼠成骨细胞OPGmRNA表达的影响

研究目的：探讨运动时去势雌性大鼠成骨细胞骨保护素(osteoprotegerin，OPG)表达变化的影响并讨论其在骨代谢变化中的意义。研究方法：24只4月龄雌性大鼠随机分为3组：正常时照组、去势组、去势后运动组。去势后运动组和去势组均行双侧卵巢切除，去势后运动组大鼠卵巢切除后在跑台上进行中等强度运动(18m／min，1h／day，5d／week)10周。10周后处死动物时血钙、血骨钙素、尿肌苷、尿羟脯氨酸进行检测；时股骨骨髓基质干细胞进行成骨细胞诱导培养，细胞培养至14天抽提细胞内总RNA，RT-PCR方法半定量检测各组细胞OPG基因mRNA表达量。主要结果和结论：去势组大鼠血钙、尿羟脯氨酸／肌苷均高于时照组，去势后运动组与时照组比较，上述指标无统计学差异。血骨钙素在3组之间无统计学差异。去势组大鼠OPG基因mRNA表达显著低于对照组，去势后运动组与时照组相比差异无显著性。雌激素缺乏导致骨吸收增强，运动可以抑制去势大鼠的骨吸收增强。雌激素缺乏后骨髓微环境中OPG基因mRNA表达降低，运动抑制去卵巢大鼠的骨吸收亢进可能与促进骨髓微环境中OPG基因表达有关。

Effects of Exercise on Expression of OPGmRNA in Osteoblasts of Ovariectomized Rats

This paper explores the effects of exercise on change of osteoprotegerin (OPG) mRNA expression in osteoblasts of ovariectomized rats and it's significance in bone metabolism.24 female rats aged at 4 months old are divided into three groups randomly:control group,ovariectomized model and ovariectomized model exercise.The ovarietomy is performed in OVX and Ex.Rats in Ex group is trained on treadmill at 18m/min for 1 hour/day and 5 days/week.The rats are sacrificed at 10 week postoperatively and biochemical testing of serum concentration of ionized calcium,BGP and urine concentrations of creatine.HOP is performed to evaluate the status of bone turnover.Marrow stromal stem cells isolated from femur are induced to differentiate into osteoblasts.Total RNA is extracted with TRIzol reagent when osteoblasts are culture for 14 days.mRNA expressions of OPG are determined with RT-PCR semi quantitatively and compared among different groups.The result shows that serum calcium,urine HOP/creatine in OVX group increase significantly comparing with control group.However,there is no significant difference between EX and CON group.mRNA expression of OPG is lower in OVX group than that of CON group,but no difference is found between Ex group and CON group.It suggests that esteogen deficiency leads to increased bone resorption and such tendency is deterred by exercise.Ovariectomy causes the decrease of OPG mRNA expression and exercise can depress this tendency,which relates to exercise preventing active bone resorption in ovariectomized rats.