肉碱补充剂可预防肥胖型 Zucker 大鼠的肥胖诱导的 II 型向 I 型肌纤维转变，并有利于骨骼肌的氧化表型。

Carnitine supplementation to obese Zucker rats prevents obesity-induced type II to type I muscle fiber transition and favors an oxidative phenotype of skeletal muscle.

机构信息

Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35390 Giessen, Germany.

Department of Sports Medicine, Justus-Liebig-University Giessen, Kugelberg 62, 35394 Giessen, Germany.

出版信息

Nutr Metab (Lond). 2013 Jul 10;10:48. doi: 10.1186/1743-7075-10-48. eCollection 2013.

DOI:10.1186/1743-7075-10-48

PMID:23842456

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC3717057/

Abstract

BACKGROUND

In the present study, we tested the hypothesis that carnitine supplementation counteracts obesity-induced muscle fiber transition from type I to type II.

METHODS

24 obese Zucker rats were randomly divided into two groups of 12 rats each (obese control, obese carnitine) and 12 lean Zucker rats were selected for lean control group. A control diet was given to both control groups and a carnitine supplemented diet (3 g/kg diet) was given to obese carnitine group for 4 wk. Components of the muscle fiber transformation in skeletal muscle were examined.

RESULTS

The plasma level of carnitine were lower in the obese control group compared to the lean control group and higher in the obese carnitine group than in the other groups (P < 0.05). Plasma concentrations of triglycerides and non-esterified fatty acids were increased in obese animals compared to lean animals and the obese carnitine group had lower level compared to the obese control group (P < 0.05). The obese carnitine group had an increased number of type I muscle fibers and higher mRNA levels of type I fiber-specific myosin heavy chain, regulators of muscle fiber transition and of genes involved in carnitine uptake, fatty acid transport, β-oxidation, angiogenesis, tricarboxylic acid cycle and thermo genesis in M. rectus femoris compared to the other groups (P < 0.05).

CONCLUSION

The results demonstrate that carnitine supplementation to obese Zucker a rat counteracts the obesity-induced muscle fiber transition and restores the muscle oxidative metabolic phenotype. Carnitine supplementation is supposed to be beneficial for the treatment of elevated levels of plasma lipids during obesity or diabetes.

摘要

背景

在本研究中，我们检验了这样一个假设，即肉碱补充可以对抗肥胖引起的肌纤维从 I 型向 II 型的转变。

方法

24 只肥胖 Zucker 大鼠被随机分为两组，每组 12 只（肥胖对照组、肥胖肉碱组），并选择 12 只瘦 Zucker 大鼠作为瘦对照组。两组对照组给予基础饮食，肥胖肉碱组给予补充肉碱的饮食（3 g/kg 饮食），共 4 周。检测骨骼肌中肌纤维转化的组成成分。

结果

与瘦对照组相比，肥胖对照组的血浆肉碱水平较低，而肥胖肉碱组的血浆肉碱水平高于其他组（P<0.05）。与瘦动物相比，肥胖动物的血浆甘油三酯和非酯化脂肪酸浓度升高，而肥胖肉碱组的水平低于肥胖对照组（P<0.05）。与其他组相比，肥胖肉碱组 I 型肌纤维数量增加，I 型肌纤维特异性肌球蛋白重链、肌纤维转化调节因子以及与肉碱摄取、脂肪酸转运、β-氧化、血管生成、三羧酸循环和产热相关的基因的 mRNA 水平升高（P<0.05）。