α-lipoic acid inhibits glycogen synthesis in rat soleus muscle via its oxidative activity and the uncoupling of mitochondria

被引:41
作者
Dicter, N [1 ]
Madar, Z [1 ]
Tirosh, O [1 ]
机构
[1] Hebrew Univ Jerusalem, Inst Biochem Food Sci & Nutr, Fac Agr Food & Environm Qual Sci, IL-76100 Rehovot, Israel
关键词
lipoic acid; insulin; oxidative stress; glycogen synthesis; redox;
D O I
10.1093/jn/131.10.3001
中图分类号
R15 [营养卫生、食品卫生]; TS201 [基础科学];
学科分类号
100403 ;
摘要
alpha-Lipoic acid (LA) is currently being investigated as a glucose-lowering agent for diabetes control; it is also considered a powerful dietary antioxidant. The objective of this study was to investigate the fate of glucose in isolated rat muscles incubated with LA and determine its effects on intramuscular redox status. Rat soleus muscles were incubated for up to 60 min with 2.4 mmol/L LA in the presence or absence of insulin. Intramuscular concentrations of LA were evaluated (uptake and reduction), and glycogen synthesis, glucose oxidation, intramuscular reactive oxygen species (ROS) production and mitochondrial membrane potential investigated. Insulin enhanced glycogen synthesis, whereas LA decreased rates by >50%. LA elevated ROS production and in combination with t-butylhydroperoxide, an oxidant, additively inhibited glycogen synthesis rates by 80%. Insulin acted as an antioxidant and attenuated ROS production by 30%. LA uncoupled the mitochondria and accelerated glucose oxidation 1.5-fold relative to the control. The glycogen synthesis pathway was found to be dependent on mitochondrial function because treatment with mitochondrial inhibitors eliminated the majority of glycogen synthesis. These data show that in this model, LA acts as a mild prooxidant, causing mitochondrial uncoupling and inhibition of glycogen synthesis. It appears that LA regulates glucose metabolism in the muscle differently than insulin.
引用
收藏
页码:3001 / 3006
页数:6
相关论文
共 38 条
[1]   MITOCHONDRIAL GENERATION OF HYDROGEN-PEROXIDE - GENERAL PROPERTIES AND EFFECT OF HYPERBARIC-OXYGEN [J].
BOVERIS, A ;
CHANCE, B .
BIOCHEMICAL JOURNAL, 1973, 134 (03) :707-716
[2]   CELLULAR PRODUCTION OF HYDROGEN-PEROXIDE [J].
BOVERIS, A ;
CHANCE, B ;
OSHINO, N .
BIOCHEMICAL JOURNAL, 1972, 128 (03) :617-&
[3]   Mitochondrial membrane potential and hydroethidine-monitored superoxide generation in cultured cerebellar granule cells [J].
Budd, SL ;
Castilho, RF ;
Nicholls, DG .
FEBS LETTERS, 1997, 415 (01) :21-24
[4]   Mitochondrial free radical generation, oxidative stress, and aging [J].
Cadenas, E ;
Davies, KJA .
FREE RADICAL BIOLOGY AND MEDICINE, 2000, 29 (3-4) :222-230
[5]   Impaired glucose transport as a cause of decreased insulin-stimulated muscle glycogen synthesis in type 2 diabetes [J].
Cline, GW ;
Petersen, KF ;
Krssak, M ;
Shen, J ;
Hundal, RS ;
Trajanoski, Z ;
Inzucchi, S ;
Dresner, A ;
Rothman, DL ;
Shulman, GI .
NEW ENGLAND JOURNAL OF MEDICINE, 1999, 341 (04) :240-246
[6]   Stimulation of glucose uptake by the natural coenzyme alpha-lipoic acid thioctic acid - Participation of elements of the insulin signaling pathway [J].
Estrada, DE ;
Ewart, HS ;
Tsakiridis, T ;
Volchuk, A ;
Ramlal, T ;
Tritschler, H ;
Klip, A .
DIABETES, 1996, 45 (12) :1798-1804
[7]   Diabetes and cardiovascular disease - A statement for healthcare professionals from the American Heart Association [J].
Grundy, SM ;
Benjamin, IJ ;
Burke, GL ;
Chait, A ;
Eckel, RH ;
Howard, BV ;
Mitch, W ;
Smith, SC ;
Sowers, JR .
CIRCULATION, 1999, 100 (10) :1134-1146
[8]   Prevalence of diabetes, impaired fasting glucose, and impaired glucose tolerance in US adults - The Third National Health and Nutrition Examination Survey, 1988-1994 [J].
Harris, MI ;
Flegal, KM ;
Cowie, CC ;
Eberhardt, MS ;
Goldstein, DE ;
Little, RR ;
Wiedmeyer, HM ;
Byrd-Holt, DD .
DIABETES CARE, 1998, 21 (04) :518-524
[9]   Stimulation by alpha-lipoic acid of glucose transport activity in skeletal muscle of lean and obese Zucker rats [J].
Henriksen, EJ ;
Jacob, S ;
Streeper, RS ;
Fogt, DL ;
Hokama, JY ;
Tritschler, HJ .
LIFE SCIENCES, 1997, 61 (08) :805-812
[10]  
Howard BV, 1999, AM J CARDIOL, V84, p28J