脊髓损伤后大鼠骨代谢和骨密度变化

目的:了解脊髓损伤后不同时期大鼠骨代谢和骨密度的变化。方法:60只SD大鼠按体重随机分为6组,对20只大鼠采用脊髓横断法在第10胸椎段横断脊髓制作完全性脊髓损伤模型,分为脊髓损伤6周和12周组;20只在同水平处切断棘突、椎板制作假手术对照组,分为假手术6周和12周组;另20只分为正常6周和12周对照组。分别在脊髓损伤后6周和12周时处死动物。结果:脊髓损伤6周、12周时,脊髓损伤组血Ca较对照组明显升高(P<0.05),碱性磷酸酶和骨钙素则较对照组无明显变化(P>0.05)。脊髓损伤6周时,股骨近端、远端骨密度(BMD)均较对照组显著降低(P<0.001),损伤12周时,除股骨近端、远端外,中段BM D也明显降低(P<0.05)。L5BMD在SCI6周和SCI12周与对照组比较差异无显著性意义(P>0.05)。结论:脊髓损伤6周时,大鼠骨代谢已发生明显改变,骨量出现明显丢失,12周时骨代谢稍有改善,但股骨骨量丢失持续存在。

The influence of spinal cord injury on bone metabolism and bone mass density in rats

Objective: To determine the changes of bone metabolism and bone mass density(BMD) in spinal cord injury(SCI). Method:Sixty SD rats were randomly divided into control groups(n=40) and experiment groups(n=20). The rats of the experiment groups were transected at the T10 spinal cord to make models of SCI, and the control groups included normal control group and sham operation group whose vertebra board and thorn were cut off at T10 level. At 6 and 12 weeks after SCI, the serum alkaline phosphatase(ALP) ?bone glaprotein(BGP)and serum calcium(Ca2+) were tested, and bone mass density was determined with dual energy X-ray. Result:when compared to control group, the serum Ca2+ in SCI groups were increased significantly at 6 and 12 weeks(P<0.05), the BMD in promixal and distal femur were decreased at 6 weeks, the BMD in middle femur were reduced at 12 weeks as well. Conclusion:The bone metabolism in SCI rats is deteriorated and BMD is decreased at 6 weeks, and the bone metabolism is improved slightly at 12 weeks.