A leucine-supplemented diet improved protein content of skeletal muscle in young tumor-bearing rats
Braz. j. med. biol. res
;
36(11): 1589-1594, Nov. 2003. graf
Artigo
em Inglês
| LILACS
| ID: lil-348287
ABSTRACT
Cancer cachexia induces host protein wastage but the mechanisms are poorly understood. Branched-chain amino acids play a regulatory role in the modulation of both protein synthesis and degradation in host tissues. Leucine, an important amino acid in skeletal muscle, is higher oxidized in tumor-bearing animals. A leucine-supplemented diet was used to analyze the effects of Walker 256 tumor growth on body composition in young weanling Wistar rats divided into two main dietary groups normal diet (N, 18 percent protein) and leucine-rich diet (L, 15 percent protein plus 3 percent leucine), which were further subdivided into control (N or L) or tumor-bearing (W or LW) subgroups. After 12 days, the animals were sacrificed and their carcass analyzed. The tumor-bearing groups showed a decrease in body weight and fat content. Lean carcass mass was lower in the W and LW groups (W = 19.9 ± 0.6, LW = 23.1 ± 1.0 g vs N = 29.4 ± 1.3, L = 28.1 ± 1.9 g, P < 0.05). Tumor weight was similar in both tumor-bearing groups fed either diet. Western blot analysis showed that myosin protein content in gastrocnemius muscle was reduced in tumor-bearing animals (W = 0.234 ± 0.033 vs LW = 0.598 ± 0.036, N = 0.623 ± 0.062, L = 0.697 ± 0.065 arbitrary intensity, P < 0.05). Despite accelerated tumor growth, LW animals exhibited a smaller reduction in lean carcass mass and muscle myosin maintenance, suggesting that excess leucine in the diet could counteract, at least in part, the high host protein wasting in weanling tumor-bearing rats.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Carcinoma 256 de Walker
/
Músculo Esquelético
/
Suplementos Nutricionais
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Leucina
/
Proteínas Musculares
Limite:
Animais
Idioma:
Inglês
Revista:
Braz. j. med. biol. res
Assunto da revista:
Biologia
/
Medicina
Ano de publicação:
2003
Tipo de documento:
Artigo
/
Documento de projeto
País de afiliação:
Brasil
/
Reino Unido
Instituição/País de afiliação:
The Babraham Institute/GB
/
Universidade Estadual de Campinas/BR
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