Kaijser L, Nye E R, Eklund B, Olsson A G, Carlson L A
Scand J Clin Lab Invest. 1978 Feb;38(1):41-7.
To see if the magnitude of carbohydrate extraction by working skeletal muscle in man is inversely correlated with the arterial free fatty acid (FFA) concentration as in the heart, eighteen healthy men were studied during dynamic forearm work with and without nicotinic acid. The extraction or release of glucose, lactate and pyruvate was determined by the simultaneous sampling of blood from the brachial artery (a) and a deep vein (dv) of the active forearm. Nicotinic acid decreased the arterial FFA concentration from 498 +/- 53 to 134 +/- 12 mumol per litre plasma and this caused a decrease in calculated extraction of FFA. However, it did not affect the extraction of glucose, which was of a magnitude similar to one third of the oxidative metabolism in both situations. One of the possible reasons of this difference compared to the human heart muscle is that the exercising skeletal muscle may utilize stored substrate to a greater extent, which makes possible shifts in substrate utilized for oxidation without changes in substrate extraction. Another reason may be that FFA utilization covers a far smaller proportion of oxidative metabolism in skeletal than in heart muscle already before nicotinic acid.
为了探究在人体中，工作的骨骼肌摄取碳水化合物的量是否像在心脏中那样与动脉血游离脂肪酸（FFA）浓度呈负相关，我们对18名健康男性在进行动态前臂运动时服用和未服用烟酸的情况进行了研究。通过同时从肱动脉（a）和活动前臂的一条深静脉（dv）采集血液，来测定葡萄糖、乳酸和丙酮酸的摄取或释放情况。烟酸使动脉血FFA浓度从每升血浆498±53微摩尔降至134±12微摩尔，这导致计算得出的FFA摄取量减少。然而，它并未影响葡萄糖的摄取，在两种情况下，葡萄糖摄取量的大小都与氧化代谢量的三分之一相似。与人类心肌相比，出现这种差异的一个可能原因是，运动的骨骼肌可能在更大程度上利用储存的底物，这使得氧化所利用的底物能够发生变化，而底物摄取量却没有改变。另一个原因可能是，在服用烟酸之前，FFA在骨骼肌氧化代谢中所占的比例就远比在心肌中要小得多。
