Affiliation:
1. Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.
Abstract
The purpose of this study was to evaluate the suitability of the glucose analogue 2-deoxyglucose (2-DG) for measurement of glucose transport activity in rat skeletal muscles in vitro when transport rates are high. The goal was to determine whether glucose phosphorylation rather than transport becomes limiting under experimental conditions normally employed in muscle incubation experiments. The rate of 2-DG uptake assayed in the presence of 8 mM 2-DG and a maximally effective concentration of insulin remained linear for > or = 60 min in the split soleus and 120 min in the epitrochlearis. Hexokinase activity assayed in skeletal muscle homogenates was not inhibited appreciably by 2-deoxyglucose 6-phosphate (2-DG-6-P) concentrations in the range of those achieved intracellularly during the linear phase of 2-DG uptake (i.e., 2-DG-6-P below approximately 30 mM). During this linear phase of 2-DG uptake, total intracellular 2-DG concentrations did not exceed 30 mM. The combined effects of contractions plus a maximally effective concentration of insulin on glucose transport activity measured at a near-saturating concentration of 2-DG were additive in the epitrochlearis and the soleus. Our results indicate that, under the conditions employed in our isolated muscle preparations, 2-DG uptake accurately reflects glucose transport activity and that 2-DG is the most appropriate glucose analogue for measurement of glucose transport activity when transport rates are high.
Publisher
American Physiological Society
Subject
Physiology (medical),Physiology
Cited by
213 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献