Di Giancamillo Alessia, Rossi Raffaella, Vitari Francesca, Pastorelli Grazia, Corino Carlo, Domeneghini Cinzia
Department of Veterinary Sciences and Technologies for Food Safety, University of Milan, 20133 Milan, Italy.
J Nutr. 2009 Oct;139(10):1867-72. doi: 10.3945/jn.109.110627. Epub 2009 Aug 26.
We investigated the effects of dietary conjugated linoleic acids (CLA) on white adipose tissue (WAT) in heavy pigs. Twelve pigs were assigned to 1 of 2 groups supplemented with either 0 or 0.75% of a CLA preparation (isomeric mixture) and were slaughtered at 159 +/- 2.3 kg live weight. Their subcutaneous WAT was analyzed by both chemical and microanatomical methods. The WAT of CLA-fed pigs tended to have a higher protein content (P = 0.064) and smaller adipocytes (P = 0.053) than that of control (CTR) pigs. The number of proliferating preadipocytes tended to be greater (P = 0.076) in pigs fed CLA, whereas the number of apoptotic adipocytes was greater (P < 0.01) than in CTR pig. Immunohistochemistry revealed that leptin (Ob) expression was lower (P = 0.048) in adipocytes from treated pigs and Western blot quantification of Ob revealed lower levels (P < 0.05) in CLA-fed pigs. The Ob receptor was not affected by dietary CLA supplementation. Tyrosine hydroxylase activity was higher (P < 0.001) in WAT of CLA fed-pigs than in CTR. It is conceivable that the increased noradrenergic activity due to dietary CLA decreases the Ob expression, although it does not diminish the lipid content of WAT, at least in heavy pigs. This article describes the interaction between CLA and Ob in the WAT of heavy pigs and we hypothesize that there is an increased noradrenergic stimulation of lipolysis directly in the target tissue.
我们研究了日粮共轭亚油酸（CLA）对肥育猪白色脂肪组织（WAT）的影响。将12头猪分为两组，分别补充0或0.75%的CLA制剂（异构体混合物），并在活重159±2.3 kg时屠宰。通过化学和显微解剖方法对其皮下WAT进行分析。与对照组（CTR）猪相比，CLA饲喂猪的WAT蛋白质含量更高（P = 0.064），脂肪细胞更小（P = 0.053）。CLA饲喂猪的增殖前脂肪细胞数量趋于增多（P = 0.076），而凋亡脂肪细胞数量比CTR猪更多（P < 0.01）。免疫组织化学显示，处理猪脂肪细胞中的瘦素（Ob）表达较低（P = 0.048），Western blot定量分析显示CLA饲喂猪的Ob水平较低（P < 0.05）。Ob受体不受日粮CLA添加的影响。CLA饲喂猪的WAT中酪氨酸羟化酶活性高于CTR猪（P < 0.001）。可以想象，日粮CLA导致的去甲肾上腺素能活性增加会降低Ob表达，尽管至少在肥育猪中它不会降低WAT的脂质含量。本文描述了肥育猪WAT中CLA与Ob之间的相互作用，我们推测在靶组织中直接存在去甲肾上腺素能对脂肪分解的刺激增加情况。
