钙网蛋白介导热处理对大鼠骨骼肌适应性变化钙调机制的研究

Calreticulin-mediated thermal treatment on the adaptation change of calmodulin mechanism in rat skeletal muscle

目的:研究应激蛋白钙网蛋白(CRT)在热处理过程中对大鼠骨骼肌适应性保护的钙调机制。方法:本研究使用递增的热处理方案对大鼠进行热干预,40只SD大鼠被随机分成安静对照组C(8只)和热处理组H(32只),其中热处理组在热干预完毕后再分为热处理即刻组(H1)、热处理后24 h组(H2)、热处理后48 h组(H3)和热处理后6 d组(H4)(n=8)。结果:热处理完成后,H2组大鼠骨骼肌肌质网Ca2+-ATP酶活性值最高,与安静对照组C比较呈非常显著性(P<0.01),H1组与安静对照组C比较,其值也呈显著性差异(P<0.05);线粒体Ca2+-ATP酶活性以H1组最高,与安静对照组C比较呈显著性差异(P<0.05),同时大鼠骨骼肌肌质网Ca2+浓度以H2组最高,H1组其次,两者与安静对照组比较呈显著性差异(P<0.05);线粒体Ca2+浓度H1与H2组值高于安静对照组C,H3及H4组值低于安静对照组C,都无差异性;热处理完毕后,H1、H2、H3组大鼠骨骼肌中应激蛋白CRT的表达量较安静对照组C显著增加。结论:在温度递增的热处理过程中,钙网蛋白对骨骼肌细胞钙平衡的失调发挥调节作用,这种热刺激产生的适应性保护对骨骼肌有很好的保护作用。

Objective： To study the protection of stress protein calreticulin（CRT） in rat skeletal muscle during the adaptation mechanism of calmodulin in the courese of heat treatment.Methods： Increased heat treatment program would be applied,40 SD rats were randomly divided into the quiet control group C（n=8） and heat-treated group H（n=32）,then the heat treatment group would be divided into immediately group（H1）,24-hour post-heat treatment group（H2）,48-hour post-heat treatment group（H3） and six days post-heat treatment group（H4）（n=8）. Results： After heat treatment,the Ca2＋-ATP activity in rat skeletal muscle sarcoplasmic reticulum in H2 group reached the highest value compared with that in the quiet control group C（P0.01）,and the value in H1 group showed significant differences compared with control group C（P0.05）;The Ca2＋-ATP activity in mitochondrial had the highest value in H1 group,compared with the quiet control group C（P0.05）,while the Ca2＋ concentration in rat skeletal muscle sarcoplasmic reticulum had the highest in group H2,followed by H1 group,both showing significant difference compared with the quiet control group（P0.05）;The Ca2＋ concentration in mitochondrial was highe in H1 and H2 group than that of the quiet control group C,and the value in H3 and H4 group was lower than that of the quiet control group C,which had no difference;After heat treatment,the expression of stress proteins of CRT from H1,H2 and H3 group in rat skeletal muscle increased significantly compared with quiet group C.Conclusion： In the process of increased heat treatment,calreticulin played the regulatory role on the imbalance of calcium homeostasis in skeletal muscle cells,and the adaptation protection from the thermal stimulation could have the very good effect on muscle.