Effects of rehabilitation approach for muscle strengthening.

背景：被动伸展是肌肉生长的刺激因素之一。为了一次性达到效果，我们不得不伸展肌肉几个小时以上。然而，这是很难使时间给拉伸肌肉为几个hours clinical.Objective.Objectives：被动拉伸，适用于短时间在几天内的内侧腓肠肌，MyoD，肌生成素，肌球蛋白重链（MHC）基因expressions.Methods：28个7周龄雄性Wister大鼠。他们被分成三组。第一组：11只大鼠在15min内重复牵拉右内侧胃楔肌15次，隔日4次。第二组大鼠连续拉伸15分钟，隔日4次。两组均以对侧肌肉不牵拉为对照。第三组为对照组，不作双侧牵拉。在最后一次拉伸后24小时，取出肌肉并提取它们的核糖核酸（mRNA）信使。结果：与对照侧相比，重复牵张肌和连续牵张肌中MyoD、myogenin和MHC的mRNA水平均升高。重复牵张组和持续牵张组MyoD和myogenin基因的表达与对照组相比无显著性差异。与对照侧相比，两组大鼠的MHCmRNA均升高。此外，有重复拉伸和控制之间的显着差异，但没有显着差异之间的连续拉伸和control group.Conclusions：MyoD，myogenin，和MHC基因表达增加被动拉伸15分钟，几天。与连续拉伸相比，这种效果在重复拉伸中尤其明显。

Background : Passive stretch is one of stimulating factors for muscle growth. To have the effect at one time, we cannot help stretching muscles for over few hours. However, it is hard to make time to give stretching muscles for a few hours clinically.Objectives : To evaluate the effect of passive stretch, applied for a short time in several days to the medial gastroeunemius muscles, on MyoD, myogenin, and myosin heavy chain (MHC) gene expressions.Methods : Twenty-eight 7-week-old male Wister rats were used. They were divided into three groups. In the first group, eleven rats were stretched right medial gastrocunemius muscles repetitively 15 times in one minute during 15 minutes, four every other days. In second group, the same number rats were stretched continuously for 15 minutes, four every other days. In the two groups, contralateral muscles were without stretch as the control side. The third group, they were not stretched both side as control goup. Twenty four hour after the last session of stretch, muscles were removed and messenger of ribonucleic acid (mRNA) of them were extracted. The mRNA levels of MyoD, myogenin, MHC were assessed by real-time polymerase chain reaction.Results : MyoD, myogenin and MHC mRNA levels increased compared with control sides, in repetitive stretch muscles and continuous stretch muscles. No difference was found in the mRNA of MyoD and myogenin gene expression after repetitive stretch group and continuous stretch group compared with control group. The MHC mRNA increased in both groups compared with control side. Furthermore there was a significant difference between repetitive stretch and control, but no significant difference between continuous stretch and control group.Conclusions : MyoD, myogenin, and MHC gene expression were increased by passive stretch for 15 minutes for several days. This effect is especially clear in repetitive stretch compared to continuous stretching.