| RRC ID |
2815
|
| 著者 |
Miyamoto L, Toyoda T, Hayashi T, Yonemitsu S, Nakano M, Tanaka S, Ebihara K, Masuzaki H, Hosoda K, Ogawa Y, Inoue G, Fushiki T, Nakao K.
|
| タイトル |
Effect of acute activation of 5'-AMP-activated protein kinase on glycogen regulation in isolated rat skeletal muscle.
|
| ジャーナル |
J Appl Physiol (1985)
|
| Abstract |
5'-AMP-activated protein kinase (AMPK) has been implicated in glycogen metabolism in skeletal muscle. However, the physiological relevance of increased AMPK activity during exercise has not been fully clarified. This study was performed to determine the direct effects of acute AMPK activation on muscle glycogen regulation. For this purpose, we used an isolated rat muscle preparation and pharmacologically activated AMPK with 5-aminoimidazole-4-carboxamide-1-beta-D-ribonucleoside (AICAR). Tetanic contraction in vitro markedly activated the alpha(1)- and alpha(2)-isoforms of AMPK, with a corresponding increase in the rate of 3-O-methylglucose uptake. Incubation with AICAR elicited similar enhancement of AMPK activity and 3-O-methylglucose uptake in rat epitrochlearis muscle. In contrast, whereas contraction stimulated glycogen synthase (GS), AICAR treatment decreased GS activity. Insulin-stimulated GS activity also decreased after AICAR treatment. Whereas contraction activated glycogen phosphorylase (GP), AICAR did not alter GP activity. The muscle glycogen content decreased in response to contraction but was unchanged by AICAR. Lactate release was markedly increased when muscles were stimulated with AICAR in buffer containing glucose, indicating that the glucose taken up into the muscle was catabolized via glycolysis. Our results suggest that AMPK does not mediate contraction-stimulated glycogen synthesis or glycogenolysis in skeletal muscle and also that acute AMPK activation leads to an increased glycolytic flux by antagonizing contraction-stimulated glycogen synthesis.
|
| 巻・号 |
102(3)
|
| ページ |
1007-13
|
| 公開日 |
2007-3-1
|
| DOI |
10.1152/japplphysiol.01034.2006
|
| PII |
01034.2006
|
| PMID |
17122373
|
| MeSH |
AMP-Activated Protein Kinases
Adenosine Triphosphate / metabolism*
Aminoimidazole Carboxamide / analogs & derivatives
Animals
Dose-Response Relationship, Drug
Enzyme Activation
Glucose / metabolism
Glycogen / metabolism*
Glycogen Phosphorylase / metabolism
Glycogen Synthase / metabolism
Glycolysis / physiology
In Vitro Techniques
Insulin / physiology
Lactic Acid / metabolism
Male
Multienzyme Complexes / metabolism*
Muscle Contraction / physiology*
Muscle, Skeletal / metabolism*
Protein Serine-Threonine Kinases / metabolism*
Rats
Rats, Sprague-Dawley
Ribonucleosides
Ribonucleotides
Time Factors
|
| IF |
3.044
|
| 引用数 |
54
|
|
WOS 分野
|
SPORT SCIENCES
PHYSIOLOGY
|
| リソース情報 |
| ラット |
|
