增龄及去睾丸大鼠骨密度和性激素因子的实验研究

Changes of BMD and sex hormone in aging male and orchiectomized rats

目的 探讨雄性大鼠增龄及去睾丸后骨密度的改变 ,性激素和细胞因子的血清水平以及他们之间的相关性。方法 30只SD雄性大鼠 ,随机分成基础对照组 (3月半龄 ) ,年龄对照组 (6月半龄 )和去睾丸组 (6月半龄 ) ,同等条件下饲养 90d ,应用HOLOGIC第 4代双能X射线 4 5 0 0W骨密度仪测各组大鼠全身骨密度 ,腰椎骨密度、股骨颈骨密度 ,并检测各组大鼠血清中的生物活性雌二醇 ,游离睾丸酮以及血清IGF 1和血清TNF a水平。结果 雄性大鼠全身骨密度和腰椎骨密度在年龄对照组和基础对照组差异无显著性 (P >0 0 5 ) ,股骨颈骨密度在年龄对照组略低于基础对照组 ,而去睾丸组又略低于年龄对照组 ,两组间比较 ,统计学上差异无显著性。在去睾丸组血清中游离的睾丸酮浓度低于年龄对照组 (P <0 0 5 ) ,而其血清中雌二醇浓度却较年龄对照组高 ,两组比较 ,差异有显著性 (P <0 0 5 )。血清IGF - 1水平在年龄对照组低于基础对照组 (P <0 0 5 ) ,在去睾丸组明显低于年龄对照组 (P <0 0 1)。血清TNF -a水平在 3组实验动物中差异无显著性 ,但血清TNF -a值与全身骨密度呈负相关 (相关系数r=- 0 384 8,P <0 0 5 )。结论 雄性大鼠与增龄有关的骨丢失过程发展缓慢 ,去睾丸后骨密度的降低以股骨颈略为显著 ,说明大鼠体内睾丸?

Objective\ To observe the changes of BMD and serum sex hormone levels in aging male and orchiectomized rats. Methods\ Thirty male SD rats were randomized into basal control group and aging control group and orchiectomized group.Ninety days after initiation of the experiment,bone mineral density was measured with dual energy X ray bone densitometer.Serum estradiol and free testosterone levels and IGF 1 and TNF α concentrations were determined by ELISA. Results\ There were changes in aging control group,compared with basal control group,including decrease in femoral neck BMD and serum IGF-1 levels.In ORX group,free testosterone concentration and IGF-1 levels decreased,compared with matched aging group. Conclusion\ Ninety day aged and ORX rats have low bone loss.Orchiectomy may cause changes in free testosterone concentration and estradiol concentration.\;