雌激素对老年雄性大鼠植入骨新骨形成的影响

The effect of estrogen on new bone formation in the implanted bone matrix in aged male rats

目的 研究雌激素对老年雄性哺乳动物的植入骨的新生骨骨面积及对全身骨代谢的影响。方法 骨基质骨片植入老年雄性大鼠 ,观察注射雌激素组、雄激素组和对照组骨组织计量学、骨生物力学、尿脱氧吡啶啉 /肌酐 (Dpd/Cr)比值 ,以及血和尿的钙、磷等的变化。结果 ( 1)新生骨骨面积 :雌激素组和雄激素组均比对照组明显增高 (P <0 0 5 ) ,雌激素组和雄激素组之间差异无显著性。 ( 2 )破骨细胞数 :雌激素组 ( 5 5± 3)个 /mm2 和雄激素组 ( 5 3± 3)个 /mm2 均显著高于对照组 ( 40± 3)个 /mm2 (P≤ 0 0 0 2 ) ,雌激素组和雄激素组之间差异无显著性。 ( 3)尿Dpd/Cr比值 (mmol/mol) :注药后5周 ,对照组 (注射溶剂 )比注药前明显升高 ( 198± 2 0vs 10 4± 7) ,雌激素组 ( 114± 16 )和雄激素组 ( 118± 19)均比对照组 ( 198± 2 0 )明显减低 ,与注药前无明显差异 ,雌激素和雄激素组之间差异无显著性。结论 雌激素和雄激素不仅能刺激老年雄性大白鼠植入骨的新生骨骨面积增加 ,也能抑制全身骨骼的骨吸收速率。本实验条件下 ,这两方面的影响 。

Objective To study the effect of estrogen on new bone formation in the implanted bone matrix in aged male rats and on general bone metabolism. Methods The aged male rats were implanted with slices of bone matrix and subcutenously injected with estrogen, androgen or the solvent for five weeks. The changes in bone histomorphometry, bio-mechanical parameters and urine deoxypyridinoline (Dpd) levels were observed as indexes of bone reabsorption. Calcium, organic phosphate, and alkalphophatase levels in serum and urine were also studied. Results (1) The areas of new bone formation were significantly larger in estrogen and androgen groups than in the control but without difference between estrogen and androgen groups. (2) The number of osteoclasts was higher in estrogen and androgen groups than in the control (P≤0002) but without difference between estrogen and androgen groups. (3) Urine Dpd/Cr ratio was lower in estrogen and androgen groups than in the control and higher in the control than that obtained 5 weeks ago but without difference between estrogen and androgen groups. Conclusion Estrogen and androgen are able to stimulate new bone formation in the implanted bone matrix and inhibit the reabsorption rate of systemic bones in aged male rats, but there was no difference between estrogen and androgen in these two respects under the conditions of this experiment