早期激素性股骨头坏死骨细胞凋亡的实验研究

目的探讨细胞凋亡在早期激素性股骨头缺血坏死中的意义。方法新西兰兔60只，雌雄不拘，体重2．6～3．5kg，随机分为实验组和对照组，每组30只。实验组予耳缘静脉注射马血清（10ml／kg）2次，每次间隔2周；马血清注射完毕2周后，连续3d腹腔内注射甲基强的松龙（45ml／kg·d）。对照组腹腔注射等量生理盐水。分别于给药后2、4、6和8周采用气栓法处死动物，切取双侧股骨头标本，行组织形态学、透射电镜观察及TUNEL法凋亡细胞检测。结果给药后4周，实验组凋亡细胞数为112．33‰±26．12‰，明显高于对照组47．01‰±22．95‰（P〈0．01）；随着时间推移，凋亡细胞逐渐增多。给药后6、8周，实验组空骨陷窝百分比分别为17．23％±3．44％、28．56％±3．45％，对照组分别为11．29％±2．89％、11．26％±2．75％，二者差异均有统计学意义（P〈0．05）。给药后6、8周透射电镜观察，实验组见部分骨细胞有完整核膜、染色质浓集、电子密度增加等凋亡特征；对照组骨细胞占据整个骨陷骨，细胞突起较多、细胞器丰富，线粒体发达。结论细胞凋亡在早期激素性股骨头缺血坏死中起重要作用。

AN EXPERIMENTAL STUDY ON OSTEOCYTE APOPTOSIS IN STEROID-INDUCED EARLY OSTEONECROSIS OF FEMORAL HEAD

OBJECTIVE: To explore the significance of osteocyte apoptosis in steroid-induced osteonecrosis of the femoral head. METHODS: Sixty New Zealand rabbits were divided into experimental group and control group (n=30). The experimental group was given 10 ml/kg of horse serum intravenously 2 times at 2 weeks intervals and an intraperitoneal injection of 45 ml/kg x d of methylprednisolone acetate for 3 days; the control group was given equal isotonic Na chloride. Osteocyte apoptosis was observe by means of TUNEL. RESULTS: The number of apoptosis in the experimental group (112.33% per hundred +/- 26.12% per hundred) was significantly higher than that in the control (47.01% per hundred +/- 22.95% per hundred) (P < 0.01) in the 4th week. With time, osteocytes apoptosis progressively increased. In the 6th and 8th weeks, the percentage of empty osteocyte lacunae in the experimental group (17.23% +/- 3.44%, 28.56% +/- 3.45%) was significantly higher than that in the control group (11.29% +/- 2.89%, 11.26% +/- 2.75%, P < 0.05). The transmission electron microscope showed that the characteristics of osteocyte apoptosis included intact nuclear membrane,c omdensed chromatin and increased electron dense. CONCLUSION: Osteocytes apoptosis may play a key role in the process of steroid-induced early osteonecrosis of the femoral head.