持续性高正加速度对咀嚼肌纤维酶组织化学特性的影响

Effects of repeated +Gz forces on masticatory muscles

目的:观察持续性高正加速度重复作用对大鼠咀嚼肌纤维酶组织化学特性的影响。方法:雄性Wistar大鼠20只随机分成对照组和实验组。对照组固定于离心机转臂上,俯卧位,头向轴心,+1Gz离心5min。实验组体位同对照组,+10Gz离心30s,间隔时+1Gz离心60s,连续每天5次,每周4天,共3周。进行咬肌和颞肌肌纤维烟酰胺腺嘌呤二核苷酸四唑还原酶(NADH-TR)和腺苷三磷酸酶(ATP酶)染色分析。结果:与对照组相比,实验组咬肌和颞肌Ⅱ型纤维横截面积减小,Ⅱ型纤维百分构成比下降。结论:持续性高正加速度重复作用导致的咬肌和颞肌损伤可能具有Ⅱ型肌纤维横截面积减小的特点。

Objective: To study the changes of the enzyme his to chemical characterization of masticatory musclesfibers under +Gz condition. Methods: 20 male Wistar rats were randomly divided into 2 groups. The control group A wasexposed to +1Gz for 5 minutes. The experimental group was repeatedly exposed to +10Gz (each for 30s, onset rate about0.5G/s, 5 times/d with +1Gz 1 minute intervals, 4d/wk, 3 weeks in total). The enzyme histochemical changes of massetermuscles and temporalis muscles fibers were analyzed by NADH-TR and ATPase staining. Results: Compared with thecontrol group, the percentage and the crossection area of type Ⅱ fibers decreased in experimental group. Conclusion:Repeated +Gz stresses could induce the arophy of type II fibers of masseter muscles and temporalis muscles.