不同海拔牦牛骨骼肌线粒体呼吸链复合酶活性及氧化应激指标的差异分析

Differential analysis of mitochondrial complex enzyme activity and oxidative stress indexes of yak skeletal muscle at different altitudes

线粒体呼吸链是实现氧化磷酸化的分子机构,被广泛证实是活性氧产生的主要来源,活性氧的积累会造成细胞氧化应激,因此为了阐明不同海拔地区牦牛骨骼肌线粒体呼吸链复合酶活性及抗氧化能力的差异,试验从高(海拔4200 m)、中(海拔3200 m)、低(海拔1900 m)海拔地区随机选择临床健康成年雄性牦牛各5头(分别分为高、中、低海拔组),屠宰后取骨骼肌采用比色法测定5种线粒体呼吸链复合酶和抗氧化关键酶的活性及氧化应激指标。结果表明:随着海拔的升高,牦牛骨骼肌线粒体呼吸链复合酶Ⅰ~Ⅴ活性均表现为逐渐降低的趋势,其中高海拔组牦牛骨骼肌线粒体呼吸链复合酶Ⅰ、Ⅲ、Ⅳ活性与中、低海拔组牦牛差异显著(P<0.05);低海拔组牦牛骨骼肌线粒体呼吸链复合酶Ⅱ、Ⅴ活性与中、高海拔组牦牛差异显著(P<0.05)。随着海拔的升高,牦牛骨骼肌中羟自由基、丙二醛(MDA)含量和谷胱甘肽过氧化物酶(GSH-Px)活性逐渐下降,且各组间显著差异(P<0.05);总抗氧化能力(T-AOC)先升高后降低,中海拔组牦牛骨骼肌显著高于低海拔组和高海拔组(P<0.05);超氧化物歧化酶(SOD)活性先下降后上升,各组间差异显著(P<0.05)。说明牦牛骨骼肌中线粒体呼吸链复合酶活性和骨骼肌的抗氧化能力也会随着海拔而改变,牦牛骨骼肌的氧自由基代谢随着环境改变是高海拔牦牛适应低氧环境的一种生理策略。

The mitochondrial respiratory chain is a molecular mechanism that achieves oxidative phosphorylation,and the mitochondrial respiratory chain is widely confirmed to be the main source of reactive oxygen species production.And the accumulation of reactive oxygen species can cause cellular oxidative stress,so in order to elucidate the difference in mitochondria complex enzyme activity and antioxidant capacity of yak skeletal muscle at various elevations,in this experiment,five clinically healthy adult male yaks which were randomly selected at three altitudes,high(4200 m above sea level),medium(3200 m above sea level)and low(1900 m above sea level)were divided into high,medium and low altitude groups respectively.After slaughter,the activity and oxidative stress indexes of five mitochondrial complex enzymes and antioxidant key enzymes of yak skeletal muscle in each group were measured by colorimetric method.The results showed that with the increase of altitude,the activity of mitochondrial complex enzymes Ⅰ to Ⅴ of yak skeletal muscle showed a gradual decreasing trend.Among them,the activities of mitochondrial complex enzymes Ⅰ,Ⅲ,Ⅳ in the high altitude group were significantly different from those in the middle and low altitude groups(P<0.05).The activities of mitochondrial complex enzymes Ⅱ and Ⅴ of yak skeletal muscle in the low altitude group were significantly different from those in the middle and high altitude groups(P<0.05).With the increase of altitude,the contents of hydroxyl radicals,MDA and GSH-Px activity of yak skeletal muscle gradually decreased,and there was significant difference between the groups(P<0.05).T-AOC increased first and then decreased,and T-AOC of yak skeletal muscle in the middle altitude group was significantly higher than those in the low altitude group and high altitude group(P<0.05);SOD activity decreased first and then increased,and the difference between the groups was significant(P<0.05).The results suggested that mitochondrial complex enzyme activity and antioxidant capacity of yak skeletal muscle also changed with altitude,and oxygen radical metabolism of yak skeletal muscle changed with the environment,which was a physiological strategy for high-altitude yaks to adapt to low oxygen environment.