Underwood K R, Means W J, Zhu M J, Ford S P, Hess B W, Du M
Department of Animal Science, University of Wyoming, Laramie, WY 82071, United States.
Meat Sci. 2008 Jun;79(2):394-402. doi: 10.1016/j.meatsci.2007.10.025. Epub 2007 Dec 3.
Marbling, or intramuscular fat, is an important factor in meat quality. As a key regulator of lipid metabolism, AMP activated protein kinase (AMPK) may be associated with intramuscular fat accumulation. Our objective was to evaluate the relationship among AMPK and its associated signaling mediators, with marbling and lean growth in beef cattle. Steers with high intramuscular fat content (High IMF, 5.71±0.36%, n=5) and low intramuscular fat content (Low IMF, 2.09±0.19%, n=5) were selected. High IMF was associated with increased tenderness (P<0.05) and backfat thickness (P<0.01). Muscle weights were higher in Low compared to High IMF (P<0.05). High IMF steers had a reduced AMPK activity (P<0.01), reduced acetyl-CoA carboxylase phosphorylation (P<0.05), and reduced total mTOR (P=0.02) content. Data provide evidence that AMPK is involved in IMF deposition in beef cattle.
大理石花纹，即肌内脂肪，是肉质的一个重要因素。作为脂质代谢的关键调节因子，AMP激活蛋白激酶（AMPK）可能与肌内脂肪积累有关。我们的目标是评估AMPK及其相关信号介质与肉牛大理石花纹和瘦肉生长之间的关系。选择了肌内脂肪含量高（高IMF，5.71±0.36%，n = 5）和肌内脂肪含量低（低IMF，2.09±0.19%，n = 5）的阉牛。高IMF与嫩度增加（P<0.05）和背膘厚度增加（P<0.01）相关。与高IMF相比，低IMF的肌肉重量更高（P<0.05）。高IMF阉牛的AMPK活性降低（P<0.01），乙酰辅酶A羧化酶磷酸化降低（P<0.05），总mTOR含量降低（P = 0.02）。数据表明AMPK参与了肉牛肌内脂肪的沉积。
