Effect of starvation and exercise on actual and total activity of the branched-chain 2-oxo acid dehydrogenase complex in rat tissues.
Effect of starvation and exercise on actual and total activity of the branched-chain 2-oxo acid dehydrogenase complex in rat tissues.
复制标题
饥饿和运动对大鼠组织中支链 2-含氧酸脱氢酶复合物的实际活性和总活性的影响。
作者：
A. Wagenmakers;J. Schepens;J. Veerkamp
饥饿不会改变骨骼肌中支链2-氧酸脱氢酶每克组织的实际活性，但根据肌肉类型不同，对总活性有不同程度的影响。活性状态（活性状态中酶的比例）在横膈膜中没有改变，而在股四头肌中减少。肝脏和肾脏的活性均有所增加，但活性状态未发生变化。在心脏和大脑中未观察到变化。与器官湿重相关的是，饥饿时全身肌肉质量的实际活动减少，而肝脏和肾脏的活动没有变化，或略有增加。未经训练的大鼠进行15和60分钟的运动（跑步机-跑步），心脏和骨骼肌中支链2-氧酸脱氢酶复合物的实际活性和活性状态略有增加。运动1 h后，肝脏和肾脏的实际活动和总活动增加，但活动状态没有变化。脑组织未见明显变化。在运动和饥饿前后，骨骼肌每克组织的实际活动都不到肝脏和肾脏组织的2%。我们的数据表明，在喂食、饥饿和运动的大鼠中，支链2-氧酸的降解主要发生在肝脏，肾脏和骨骼肌的降解程度较小。
Starvation does not change the actual activity per g of tissue of the branched-chain 2-oxo acid dehydrogenase in skeletal muscles, but affects the total activity to a different extent, depending on the muscle type. The activity state (proportion of the enzyme present in the active state) does not change in diaphragm and decreases in quadriceps muscle. Liver and kidney show an increase of both activities, without a change of the activity state. In heart and brain no changes were observed. Related to organ wet weights, the actual activity present in the whole-body muscle mass decreases on starvation, whereas the activities present in liver and kidney do not change, or increase slightly. Exercise (treadmill-running) of untrained rats for 15 and 60 min causes a small increase of the actual activity and the activity state of the branched-chain 2-oxo acid dehydrogenase complex in heart and skeletal muscle. Exercise for 1 h, furthermore, increased the actual and the total activity in liver and kidney, without a change of the activity state. In brain no changes were observed. The actual activity per g of tissue in skeletal muscle was less than 2% of that in liver and kidney, both before and after exercise and starvation. Our data indicate that the degradation of branched-chain 2-oxo acids predominantly occurs in liver and to a smaller extent in kidney and skeletal muscle in fed, starved and exercised rats.