Carboidratos

revisão

Regulação do metabolismo de glicose e ácido graxo no músculo esquelético durante exercício físico
Regulation of glucose and fatty acid metabolism in skeletal muscle during contraction
Leonardo R. Silveira1,2, Carlos Hermano da Justa Pinheiro3,
Claudio C. Zoppi4, Sandro M. Hirabara5, Kaio F. Vitzel3, Reinaldo A. Bassit3,
Carol G. Leandro6, Marina R. Barbosa1, Igor H. Sampaio2, Iracema H. P. Melo6,
Jarlei Fiamoncini3, Everardo M. Carneiro4, Rui Curi3

SUMÁRIO

Metab. 2011;55(5):303-13
Descritores
Metabolismo mitocondrial; exercício prolongado; ciclo glicose-ácido graxo

SUMMARY
The glucose-fatty acid cycle explains the preference for fatty acid during moderate and long duration physical exercise. In contrast, there is a high glucose availability and oxidation rate in response to intense physical exercise. The reactive oxygen species (ROS) production during physical exercise suggests that the redox balance is important to regulate of lipids/carbohydrate metabolism. ROS reduces the activity of the Krebs cycle, and increases the activity of mitochondrial uncoupling proteins. The opposite effects happen during moderate physical activity. Thus, some issues is highlighted in the present review: Why does skeletal muscle prefer lipids in the basal and during moderate physical activity? Why does glucose-fatty acid fail to carry out their effects during intense physical exercise? How skeletal muscles regulate the lipids and carbohydrate metabolism during the contraction-relaxation cycle? Arq Bras Endocrinol Metab. 2011;55(5):303-13

INTRODUÇÃO

H

á 40 anos, Randle e cols. (1) propuseram a existência de uma competição entre glicose e ácidos graxos (AG) como substratos para a síntese de ATP no músculo esquelético, cardíaco e adipócitos. Nesse processo, foi demonstrado que, sob elevada disponibilidade

Arq Bras Endocrinol Metab. 2011;55/5

Correspondence to:
Leonardo R. Silveira
Escola de Educação Física e
Esporte de Ribeirão