Abstract：
This study aimed to characterize the effects of different dietary forms of supplemental manganese (Mn) on hepatic lipid deposition, gene expression, and enzyme activity in liver fat metabolism in 42-day-old broiler chickens. In total 420 one day-old Arbor Acres (AA) broilers (rooster: hen = 1:1) were assigned randomly based on body weight and sex to one of six treatments (ten replicate cages per treatment and seven broilers per replicate cage) in a completely randomized design using a 2 (sex) × 3 (diet) factorial arrangement. The three diets were basal control diets without Mn supplementation and basal diets supplemented with either Mn sulfate or Mn proteinate. No sex × diet interactions were observed in any of the measured indexes; thus, the effect of diet alone was presented in this study. Dietary Mn supplementation increased Mn content in the plasma and liver, adipose triglyceride lipase (ATGL) activity, and ATGL mRNA and its protein expression in the liver by 5.3%-24.0% (P < 0.05), but reduced plasma triglyceride (TG), total cholesterol (TC), and low-density lipoprotein (LDL-C) levels, liver TG content, fatty acid synthase (FAS) and malic enzyme (ME) activities, mRNA expression of sterol regulatory element-binding protein 1 (SREBP1), FAS, stearoyl-coA desaturase (SCD), and ME, as well as the protein expression of SREBP1 and SCD in the liver by 5.5%-22.8% (P < 0.05). No differences were observed between the two Mn sources in all of the determined parameters. Therefore, it was concluded that dietary Mn supplementation, regardless of Mn source, decreased hepatic lipid accumulation in broilers by inhibiting SREBP1 and SCD expression, FAS and ME activities, and enhancing ATGL expression and activity.
摘要：
本研究旨在表征不同膳食形式的补充锰（Mn）对肝脏脂质沉积的影响，基因表达，42日龄肉鸡肝脏脂肪代谢酶活性。根据体重和性别，将总共420只一天大的Arbor英亩（AA）肉鸡（公鸡：母鸡=1：1）随机分配给六种处理方法之一（每种处理10个重复笼子，每种重复笼子7只肉鸡）使用2（性别）×3（饮食）因子排列的完全随机设计。这三种饮食是不添加Mn的基础对照饮食和补充Mn硫酸盐或Mn蛋白盐的基础饮食。在任何测量指标中均未观察到性别×饮食相互作用；因此，在这项研究中提出了单独饮食的效果。膳食补充锰可增加血浆和肝脏中的锰含量，脂肪甘油三酯脂肪酶（ATGL）活性，ATGLmRNA及其蛋白在肝脏中的表达降低了5.3%-24.0%(P<0.05),但降低血浆甘油三酯（TG），总胆固醇(TC),低密度脂蛋白(LDL-C)水平,肝脏TG含量，脂肪酸合成酶（FAS）和苹果酸酶（ME）活性，固醇调节元件结合蛋白1（SREBP1）的mRNA表达，FAS,硬脂酰辅酶A去饱和酶（SCD），而我,以及SREBP1和SCD在肝脏中的蛋白表达降低了5.5％-22.8％（P<0.05）。在所有确定的参数中,在两种Mn源之间没有观察到差异。因此,结论是膳食补充锰，无论Mn来源如何，通过抑制SREBP1和SCD表达减少肉鸡肝脏脂质积累，FAS和ME活动，增强ATGL的表达和活性。
