氯化胆碱对尾吊大鼠比目鱼肌肌萎缩对抗效果的观察

Prophylactic Effects of Choline Chloride on Muscle Atrophy in Tail-suspended Rats

目的探讨氯化胆碱对尾吊大鼠比目鱼肌肌萎缩的影响。方法按体重配对原则将24只雌性SD大鼠分为对照组(CON)、尾吊组(TS)与尾吊给药组(TS+Cch),每组8只。尾部悬吊法建立模拟失重模型,1/2尾吊大鼠按150mg/kg的剂量用氯化胆碱灌胃,连续14d。Ca2+-ATPase法测定比目鱼肌(SOL)的mATPase活性,常规方法制作石蜡组织切片。结果1)以氯化胆碱灌胃后,尾吊大鼠SOL中Ⅰ型肌纤维比例明显升高,Ⅱ型肌纤维比例明显降低,P<0.001;2)以氯化胆碱灌胃后,尾吊大鼠SOL的肌束之间间隙减小,Ⅰ型肌纤维横截面积(CSA)明显升高,P<0.001,Ⅱ型肌纤维CSA和单根肌纤维的平均CSA亦明显高于尾吊组,P<0.05;3)以氯化胆碱灌胃后,尾吊大鼠SOL的梭内肌纤维中,一核链纤维的mATPase染色呈阴性,其它各纤维与尾吊组相同,均呈阳性。结论氯化胆碱对模拟失重条件下大鼠SOL慢肌向快肌的转化与模拟失重引起的肌萎缩均有显著的对抗作用。

Objective To study the effects of choline chloride on activities of myosin adenosine triphosphatase （mATPase） of muscle fibres and muscle atrophy in tail-suspended rats. Method Twentyfour adult female Sprague-dawley rats were averagely divided into 3 groups matched for body mass：control group（CON）, tail suspension group （TS） and tail suspension group associated with choline chloride（TS ＋ Cch）. Weightlessness was simulated by 14 d tail suspension of rats;gastric lavage with choline chloride was given to 1/2 of the rats during tail suspension （15 mg/kg body weight, i. g. ）. Activities of myosin adenosine triphosphatase （mATpase） of intrafusal and extrafusal fibres in soleus （SOL） muscle were determined by Ca^2＋-ATPase method. Paraffin sections of the soleus muscle were prepared by routine histochemistry method. Result After tail suspension for 14 d it was found ： 1） percentage of typeⅡ fibre in SOL of rats treated with choline chloride decreased distinctly as compared with that in the untreated rats （P 〈0. 001） ; 2） gaps of fascicles were closer in choline chloride treated group, and cross sectional area （CSA） of （type Ⅰ and Ⅱ ） all increased obviously as compared with those in untreated group （P 〈 0. 001 ） ; 3 ） the activities of mATPase in intrafusal fibres were similar to the two groups except one nuclear chain fibre. Conclusion Choline chloride effectively prevents muscle atrophy, as well as the transformation of slow-twitch muscle to fast-twitch muscle caused by tail suspension. It is also showed that the suppression on the increase of mATPase activities caused by weightlessness might be the essential mechanism.