静力负荷对大鼠骨骼肌线粒体及肌浆网功能的影响

目的：了解静力负荷作用下对骨骼肌线粒体及肌浆网功能的影响。方法：选择16只健康雄性Wistar大鼠,随机分为对照组、负荷组,每组8只。将大鼠麻醉后游离其左下肢比目鱼肌远端,负荷组施加100 g负荷,持续时间为90 min。在4℃条件下,9 000 r/min离心20 min分离比目鱼肌线粒体;40 000 r/min离心15 min,分离肌浆网,分别检测骨骼肌线粒体及肌浆网Ca2＋浓度、Ca2＋-ATPase活性和丙二醛（malondialchehyche,MDA）水平。结果：负荷组与对照组比较,线粒体Ca2＋浓度增加111.11%,Ca2＋-ATPase活力下降25.88%,MDA含量增加188.57%,差异均有显著性（P〈0.01）;肌浆网Ca2＋浓度下降75.89%,Ca2＋-ATPase活力下降61.49%,MDA含量增加122.86%,差异均有显著性（P〈0.01）;结论：静力负荷可致大鼠骨骼肌线粒体钙超载和肌浆网摄钙能力下降,肌浆网、线粒体膜Ca2＋-ATPase活力下降、MDA增多。

Effects of Static Load on the Function of Mitochondria and Sarcoplasmic Reticulum in Rats' Skeletal Muscle

Objective:To study the effects of static load on the function of mitochondria and sarcoplasmic reticulum of skeletal muscle.Methods:16 healthy male Wistar rats were randomly divided into control group and load group(8 rats in each).Distal end of soleus of lower left limb was isolated after anesthesia.Load group was given 100 g load and 90 min.Mitochondria was separated under the condition of 4 ℃,9 000 r/min for 20 min and sarcoplasmic reticulum was separated under the condition of 4 ℃,40 000 r/min for 15 min.Ca2+ concentrations,Ca2+-ATPase activities and malondialchehyche(MDA) levels were detected.Results:Ca2+ concentration increased 111.11%,Ca2+-ATPase activity decreased 25.88% and MDA level increased 188.57% of mitochondria in load group compared with control group.There had significant differences(P<0.01).Ca2+ concentration deceased 75.89%,Ca2+-ATPase activity decreased 61.49%,MDA level increased 122.86% of sarcoplasmic reticulum in load group compared with control group.There had significant differences(P<0.01).Conclusion: Static load can induce calcium overload of mitochondria and decrease of calcium uptake of sarcoplasmic reticulum in rats’ skeletal muscle,and decrease of Ca2+-ATPase activity and increase of MDA of mitochondria and sarcoplasmic reticulum.