Department of Animal Science, Shandong Agricultural University, Taian, Shandong 271018, PR China.
Comp Biochem Physiol C Toxicol Pharmacol. 2010 May;151(4):447-54. doi: 10.1016/j.cbpc.2010.01.010. Epub 2010 Feb 4.
Effects of dexamethasone (DEX) and mild feed restriction on the uptake and utilization of fatty acids in skeletal muscle of broiler chicks (Gallus gallus domesticus) were investigated. Male Arbor Acres chicks (7-days old, n=30) were injected with DEX or saline for 3days, and a feed restriction group was included. DEX enhanced circulating very low density lipoprotein (VLDL) level and the lipid accumulation in both adipose and skeletal muscle tissues. Compared with the control, liver-carnitine palmitoyltransferase 1 (L-CPT1) and AMP-activated protein kinase (AMPK) alpha2 mRNA level of M. biceps femoris (BF) were down-regulated significantly by DEX, while mRNA expression of lipoprotein lipase (LPL), fatty acid transport protein 1 (FATP1), heart-fatty acid binding protein (H-FABP), long-chain acyl-CoA dehydrogenase (LCAD), activities of LPL and AMPK in both skeletal muscles were not obviously affected. Feed restriction increased the mRNA expression of LPL, L-CPT1 and LCAD of M. pectoralis major (PM), and FATP1, H-FABP, L-CPT1 and LCAD of BF. In conclusion, DEX retards the growth of body mass but facilitates lipid accumulation in both adipose and skeletal muscle tissues. In contrast to the favorable effect of mild feed restriction, DEX did not alter the uptake of fatty acids in the skeletal muscle. The result suggests that DEX may promote intramyocellular lipid accumulation by suppressed fatty acid oxidation while mild feed restriction improved fatty acid oxidation in skeletal muscle, especially in red muscle. Glucocorticoids (GCs) regulated muscle fatty acid metabolism in a different way from energy deficit caused by mild feed restriction.
研究了地塞米松（DEX）和轻度饲料限制对肉鸡（Gallus gallus domesticus）骨骼肌中脂肪酸摄取和利用的影响。雄性 Arbor Acres 小鸡（7 日龄，n=30）注射 DEX 或生理盐水 3 天，并包括一个饲料限制组。DEX 增强了循环极低密度脂蛋白（VLDL）水平和脂肪在脂肪组织和骨骼肌组织中的积累。与对照组相比，DEX 显著下调了 M. biceps femoris（BF）的肝肉碱棕榈酰转移酶 1（L-CPT1）和 AMP 激活蛋白激酶（AMPK）α2 mRNA 水平，而脂蛋白脂肪酶（LPL）、脂肪酸转运蛋白 1（FATP1）、心脏脂肪酸结合蛋白（H-FABP）、长链酰基辅酶 A 脱氢酶（LCAD）的 mRNA 表达，以及骨骼肌中 LPL 和 AMPK 的活性均未受明显影响。饲料限制增加了 M. pectoralis major（PM）的 LPL、L-CPT1 和 LCAD 的 mRNA 表达，以及 BF 的 FATP1、H-FABP、L-CPT1 和 LCAD 的 mRNA 表达。总之，DEX 减缓了体重的增长，但促进了脂肪在脂肪组织和骨骼肌组织中的积累。与轻度饲料限制的有利影响相反，DEX 并未改变骨骼肌中脂肪酸的摄取。结果表明，DEX 可能通过抑制脂肪酸氧化来促进肌内脂质积累，而轻度饲料限制则改善了骨骼肌，特别是红肌中的脂肪酸氧化。糖皮质激素（GCs）对肌肉脂肪酸代谢的调节方式与轻度饲料限制引起的能量不足不同。
