Role of pyruvate dehydrogenase kinase 4 in regulating PDH activation during acute muscle contraction.
Appl Physiol Nutr Metab
; 37(1): 48-52, 2012 Feb.
Article
en En
| MEDLINE
| ID: mdl-22196220
The oxidation of carbohydrates in mammals is regulated by the pyruvate dehydrogenase (PDH) complex, which is covalently regulated by four PDH kinases (PDK1-4) and two PDH phosphatases (PDP1-2) unique to the PDH complex. To investigate the role that PDK4 plays in regulating PDH activation (PDHa) during muscle contraction, mouse extensor digitorum muscle was removed from wild type (WT) and PDK4-knockout (PDK4-KO) mice after a 24 h fast and stimulated for 3 min either at 10 Hz (low-intensity contraction), 40 Hz (moderate-intensity contraction), or allowed to rest. Force was recorded and muscle PDHa activity and metabolite concentrations were measured. PDHa activity was â¼2.5-fold higher at rest in PDK4-KO mice than WT mice (P = 0.009) and â¼2-fold higher in PDK4-KO mice at both 10 Hz (P < 0.001) and 40 Hz (P < 0.001). Force relative to muscle weight was similar at 10 Hz, but was 5.8 ± 0.7 mN·g(-1) in PDK4-KO mice and 3.5 ± 0.7 mN·g(-1) in WT mice at 40 Hz (P < 0.001), with a similar rate of fatigue in both genotypes. From these results it was concluded that PDK4 plays a role in reducing PDHa activity during low to moderate-intensity muscle stimulation, and that absence of PDK4 and the subsequent changes in carbohydrate utilization may alter force production.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Complejo Piruvato Deshidrogenasa
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Proteínas Serina-Treonina Quinasas
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Músculo Esquelético
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Metabolismo de los Hidratos de Carbono
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Contracción Muscular
Límite:
Animals
Idioma:
En
Revista:
Appl Physiol Nutr Metab
Asunto de la revista:
CIENCIAS DA NUTRICAO
/
FISIOLOGIA
/
MEDICINA ESPORTIVA
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METABOLISMO
Año:
2012
Tipo del documento:
Article
País de afiliación:
Canadá
Pais de publicación:
Canadá