日粮共轭亚油酸对黄羽肉鸡腹脂沉积的影响及机理研究

选择1日龄黄羽肉鸡60只，随机分成2组。在实验组中添加3%共轭亚油酸(conjugated linoleic acid，CLA)，对照组日粮中添加3%的食用菜籽油。49日龄屠宰，采集腹部脂肪组织。用RT-PCR方法，以β-actin为内标，相对定量测定腹脂中鸡生长激素受体（cGHR）、胰岛素样生长因子-1（cIGF-1）、胰岛素样生长因子Ⅰ型受体（cIGF-ⅠR）、过氧化物增殖剂活化受体γ（cPPARγ）、脂联素（cAdiponectin）及其Ⅰ型受体（cAdipoⅠR）的mRNA丰度。结果显示：CLA处理使肉鸡的腹脂沉积下降了20.93%（P<0.05），分别使腹脂中鸡cGHR mRNA和cPPARγ mRNA降低了24.74%（P<0.05）和66.52%（P<0.01）；而对cIGF-1、cIGF-ⅠR、cAdiponectin、cAdipoⅠR 基因表达无显著影响（P>0.05）；数据提示：CLA降低肉鸡脂肪沉积的作用可能通过GH途径和PPARγ通路介导，而与IGF-1和（或）GH-IGF-1途径、Adiponectin 的作用无关。

Effect of dietary Conjugated linoleic acid (CLA) on Abdominal Fat Deposition in Yellow Broiler Chickens and its possible Mechanism

A totle of sixty one-day-old Yellow brioler chickens were alloted into treatment and control groups. The treatment group was fed with the diet supplemented with 3% conjugated linoleic acid(CLA) for 48d, while control group was fed with the diet supplemented with 3% rapeseed oil. Chickens were slaughtered in each group at the age of 49 d, and abdominal adipose tissue was sampled. The total RNA was extracted from adipose tissue to measure the abundance of the chicken growth hormone receptor（cGHR）, insulin-like growth factor 1（cIGF-1）, insulin-like growth factor Ⅰreceptor（cIGF-ⅠR）, peroxisome proliferator-activated receptor gamma（cPPARγ）, cAdiponectin and cAdipoⅠR mRNA by RT-PCR using β-actin as an internal standard. Results showed that the CLA decreased the abdominal fat index by 20.93%（P<0.05）. CLA down-regulated the relative abundance of cGH-R mRNA and PPARγ mRNA in abdominal adipose tissue by 24.74%（P<0.05）and 66.52 %（P<0.01）respectively. However, no differences in the relative abundance of cIGF-1, cIGF-ⅠR, cAdiponectin, and cAdipoⅠR mRNA in abdominal adipose tissue between CLA treatment group and control group were found（P>0.05）. The data demonstrated that CLA inhibitted abdominal fat deposition preadipocytes via down-regulation of PPARγ, in broiler chicken may determine by decreasing the GH-R available for GH, and by inhibiting the differentiation of but independent of IGF and (or) GH-IGF pathway or adiponectin action.