目的通过对去势大鼠加载不同时段的低载荷机械振动,探讨不同的振动持续时间对骨质疏松大鼠骨组织成骨相关蛋白表达的影响。方法 6个月龄雌性Wistar大鼠24只,随机分为8周去势对照组(C8)、12周去势对照组(C12)、8周振动组(V8)和12周振动组(V12)。所有大鼠接受去势手术1周后开始实施振动试验,对V8组与V12组大鼠分别加载35 Hz、0.25 g的低载荷机械振动,每天15 min;去势对照组不做处理。8周与12周后分两批断颈处死大鼠,采用Western blot技术检测各组大鼠成骨相关蛋白BMP-2、p-ERK、Runx2、OCN的表达。结果低载荷机械振动能够显著上调去势大鼠骨组织BMP-2、p-ERK、Runx2和OCN的蛋白表达水平(P〈0.01),随着振动时间的延长,V12组较V8组蛋白含量分别增加了22.61%(P〈0.05)、27.96%(P〈0.01)、25.85%(P〈0.01)、27.05%(P〈0.01);去势对照组间各蛋白表达水平无明显差异(P〉0.05)。结论低载荷机械振动能够上调骨组织成骨相关蛋白的表达水平,并随着振动时间的增加显现出更为优越的成骨作用。
Objective To investigate the effects of different vibration durations on expression level of osteogenesis-related proteins by loading low intensity mechanical vibration in the ovariectomized(OVX) rats.Methods Twenty-four 6-month old female Wistar rats were ovariectomized and then randomly divided into 8-week-control group(C8),12-week-control group(C12),8-week-vibration group(V8),and 12-week-vibration group(V12).Vibration treatment was started one week after all the rats were ovariectomized.Rats in both V8 and V12 groups were loaded with 35 Hz,0.25 g low intensity mechanical vibration for 15 minutes per day.C8 and C12 groups served as control without any treatment.Rats were executed in batch at 8th and 12th week,respectively,to analyze expression level of osteogenesis-related proteins,including BMP-2,p-ERK,Runx2 and OCN.Results Low-intensity mechanical vibration enhanced the osteogenesis-related protein expression in OVX rats(P〈0.01).With the extension of vibration duration,the osteogenesis related proteins BMP-2、p-ERK、Runx2 and OCN in V12 group were increased by 22.61%(P〈0.05),27.96%(P〈0.01),25.85%(P〈0.01),27.05%(P〈0.01),respectively,as compared with V8 group.But for the control groups,no significant differences were found in expression level of osteogenesis-related proteins.Conclusions The low intensity mechanical vibration could elevate expression level of osteogenesis-related proteins,and the osteogenesis was enhanced with the extension of vibration duration.