Impact of 1 wk of diabetes on the regulation of myocardial carbohydrate and fatty acid oxidation
Impact of 1 wk of diabetes on the regulation of myocardial carbohydrate and fatty acid oxidation
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DOI：
10.1152/ajpendo.1999.277.2.e342
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发表时间：
1999-08-01
影响因子：
5.1
通讯作者：
Forder, JR
中科院分区：
文献类型：
--
作者：
Chatham, JC;Gao, ZP;Forder, JR
本研究旨在探讨增加外源性棕榈酸浓度对对照和1周糖尿病大鼠心脏碳水化合物和棕榈酸氧化的影响。心脏灌注葡萄糖、[3-C-13]乳酸和[U-C-13]棕榈酸酯。底物氧化速率通过结合组织提取物的C-13-NMR谷氨酸同位素分析和耗氧量测量来确定。糖尿病后，棕榈酸盐浓度低（0.1 mM）但不高（1.0 mM）时，碳水化合物氧化明显抑制。外源性棕榈酸盐浓度增加10倍，导致棕榈酸盐对能量产生的贡献在对照组增加7倍，但在糖尿病组仅增加30%。因此，在0.1 mM棕榈酸时，糖尿病组的脂肪酸氧化率高于对照组；但在1.0 mM脂肪酸氧化时，其活性明显降低。因此，糖尿病1周后，碳水化合物和脂肪酸代谢的主要差异主要发生在外源性棕榈酸盐浓度较低而不是较高的情况下。
The aim of this study was to investigate the effect of increasing exogenous palmitate concentration on carbohydrate and palmitate oxidation in hearts from control and 1-wk diabetic rats. Hearts were perfused with glucose, [3-C-13]lactate, and [U-C-13]palmitate. Substrate oxidation rates were determined by combining C-13-NMR glutamate isotopomer analysis of tissue extracts with measurements of oxygen consumption. Carbohydrate oxidation was markedly depressed after diabetes in the presence of low (0.1 mM) but not high (1.0 mM) palmitate concentration. Increasing exogenous palmitate concentration 10-fold resulted in a 7-fold increase in the contribution of palmitate to energy production in controls but only a 30% increase in the diabetic group. Consequently, at 0.1 mM palmitate, the rate of fatty acid oxidation was higher in the diabetic group than in controls; however, at 1.0 mM fatty acid oxidation, it was significantly depressed. Therefore, after 1 wk of diabetes, the major differences in carbohydrate and fatty acid metabolism occur primarily at low rather than high exogenous palmitate concentration.