Alterations in enzymes involved in fat metabolism after acute and chronic altitude exposure
Alterations in enzymes involved in fat metabolism after acute and chronic altitude exposure
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DOI：
10.1152/jappl.2001.90.1.17
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发表时间：
2001-01-01
影响因子：
3.3
通讯作者：
Mazzeo, RS
中科院分区：
文献类型：
--
作者：
Kennedy, SL;Stanley, WC;Mazzeo, RS
本研究的目的是研究模拟海拔4300米(446毫米汞柱)的急性(24小时)和慢性(5周)低压低氧暴露对脂肪代谢酶的影响。心脏、肝脏和骨骼肌均取自32只雄性SD大鼠。高原暴露没有影响任何组织中柠檬酸合成酶的活性，这表明线粒体含量没有变化。与对照组相比，急性和慢性高原暴露均显著降低心脏中肉碱棕榈酰转移酶-I(CPT-I)的活性。与对照组动物相比，急性和慢性暴露后，趾长伸肌CPT-I活性也有类似的降低。比目鱼肌或肝脏的CPT-I活性不受海拔暴露的影响。与对照组相比，慢性暴露组动物心脏3-羟基辅酶A脱氢酶(β-HAD)活性显著降低。在急性动物和对照动物的心脏中，没有发现β-HAD活性的差异。驯化动物和急性动物的肝脏β-HAD活性与对照组相比也显著降低。只有慢性动物的股四头肌β-HAD活性与对照组相比降低。这些数据表明，适应高原选择性地减少了心脏、肝脏和选定骨骼肌中脂肪利用和氧化的关键酶。
The purpose of this study was to examine the effect of acute (24 h) and chronic (5 wk) hypobaric hypoxic exposure equivalent to a simulated altitude of 4,300 m (446 mmHg) on the enzymes of fat metabolism. Heart, liver, and skeletal muscle were taken from 32 male Sprague-Dawley rats. Altitude exposure did not affect the activity of citrate synthase in any of the tissues, suggesting that mitochondrial content was unchanged. Carnitine palmitoyltransferase-I (CPT-I) activity was significantly reduced in the heart by both acute and chronic high altitude exposure compared with controls. A similar reduction was found for CPT-I activity in extensor digitorum longus after acute and chronic exposure compared with control animals. CPT-I activity was not affected by altitude exposure in the soleus muscle or the liver. 3-Hydroxyacyl-CoA dehydrogenase (beta -HAD) activity was significantly depressed in the hearts of chronically exposed animals compared with controls. No difference between acute and control animals was found in the heart for beta -HAD activity. Liver beta -HAD activity was also significantly decreased in the acclimatized as well as in the acute animals compared with the control group. Quadriceps beta -HAD activity was reduced for the chronic animals only compared with controls. These data suggest that acclimatization to high altitude selectively decreases key enzymes in fat utilization and oxidation in the heart, liver, and select skeletal muscles.