【摘要】 目的观察有氧运动对发育期大鼠骨骼肌肌纤维的形态学影响。方法本实验以雄性发育期(3-13周龄)wistar大鼠为研究对象,采用动物跑台,以坡度5%,速度15m/min的运动负荷,进行有氧运动训练,1h/d,5d/w。在训练3周(3周运动组,T3W)、6周(6周运动组,T6W)和9周(3周运动组,T9W)后,取大鼠腓肠肌内侧头进行冰冻切片,琥珀酸脱氢酶(SDH)胆碱酯酶(AchE)联合染色法,光镜下观察各型肌纤维的变化。结果各运动组各型肌纤维的横截面积、平均直径呈进行性增长,其中T6W组和T9W组的红肌、中间肌纤维的横截面积和平均直径都显著高于各对照组(P<0.05,P<0.01),T3W组、T6W组和T9W组白肌纤维的横截面积和平均直径显著高于各对照组(P<0.01)。各运动组红肌纤维百分比未见明显变化(P>0.05);T6W组和T9W组的中间肌纤维百分比较T3W组显著增加(P<0.01),分别增加10.31%和10.60%,而白肌纤维的百分比显著降低(P<0.01),分别降低11.19%和11.03%。结论有氧运动对发育期大鼠骨骼肌各型肌纤维有明显的促增长作用,并可引起白肌纤维向中间肌纤维的转变,肌纤维的形态结构不仅同运动方式及运动负荷有关,同时还与发育的年龄有着密切的相关。更多还原

【Abstract】 Objective The purpose of this study was to investigate the impact of aerobic exercise on the skeletal muscle of the developing rats. Methods Male wistar rats of development stage (3W-13W) exercised treadmill for 3 weeks ( Group T3W), 6 weeks(Group T6W)and 9 weeks(Group T9W )respeceively,for 1h/day at velocity up to 15m/min , degree+5, 5 days/week. Frozen sections of medial gastrocnemius muscle were visualized using combined staining of succinate dehydrogenase and acetylcholine esterase. Changes in area and mean diameters of the three muscle fibers were calculated under light microscope. Results The aera and mean diameters of red, intermediate and white muscles increased gradually as exercise time prolonged. Aera and mean diameters of the red and the intermedial exercised muscles fibers in group T6W and T9W , as well as white muscles in exercised groups T3W ,T6W and T9W were significantly higher than those in control (P<0.05,P<0.01). Percentages of the intermedial muscles fibers in group T6W and group T9W were 10.31% and 10.60% respectively higher than those in control , while the white fibers were 11.19% and 11.03% respectively lower than those in control . Conclusion Aerobic exercise facilitates the growth of development stage skeletal muscles, and may cause a transformation of white fibers to intermedial fibers. The size of skeletal muscles is associated with the exercise styles and exercise levels and also the development stage.更多还原