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Control of intramuscular fat accumulation in porcine muscle by dietary lysine levels
Author(s) -
Katsumata Masaya,
Matsumoto Mitsuhito,
Kawakami Shinichi,
Ishida Aiko,
Kyoya Takahito,
Nakashima Kazuki,
Kaji Yuji,
Takada Ryozo
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.90.2
Subject(s) - lysine , intramuscular fat , oxidative phosphorylation , medicine , endocrinology , glut4 , biology , chemistry , biochemistry , insulin , glucose uptake , amino acid
Pigs of six weeks of age were given a control or low lysine (LL) diet for three weeks. GLUT4 mRNA expression was up‐regulated by the LL diet in l. dorsi and rhomboideus muscles. Activities of citrate synthase were higher in those two muscles of the LL group suggesting that oxidative function of the muscles was enhanced by dietary low lysine. Thus, we determined proportion of oxidative myofiber. Indeed, proportion of oxidative fiber was higher in the LL group than in the control group. As higher triglyceride and/or intramuscular fat (IMF) content are associated with higher proportion of oxidative myofiber, we hypothesized that accumulation of IMF might be promoted by dietary low lysine. To test this hypothesis, a low lysine diet was given to finishing pigs for two months. IMF contents in l. dorsi of the pigs given a low lysine diet were twice higher than those of the control group. We also elucidated effects of dietary lysine levels on expression of adipogenesis related genes in l. dorsi and rhomboideus muscles of growing pigs; abundances of mRNA of PPARγ tended to be higher in the LL group whereas dietary lysine levels did not affect that of C/EBPα. We infer that differentiation of preadipocytes to adipocytes is not involved in promoted accumulation of IMF due to dietary low lysine in porcine muscle.