短期限饲对家兔肝脏和骨骼肌脂质代谢的影响

Effects of Short-Term Feed Restriction on Lipid Metabolism in Liver and Skeletal Muscle of Rabbits

本试验旨在研究短期限饲对家兔肝脏和骨骼肌中脂质代谢相关基因表达的影响,以阐明短期限饲下家兔脂质代谢的调节机制。选取40日龄、体重相近、健康状况良好的商品代伊拉肉兔40只,随机分为对照组(自由采食)和试验组(限饲,饲喂量为对照组的70%左右),每组20个重复(公母各占1/2),每个重复1只。试验期为5 d。结果显示:短期限饲显著降低了家兔肝脏指数(P<0.05),有降低家兔后腿肌重量的趋势(P=0.074 3),对家兔前腿肌、背腰肌、总肌肉(前腿肌+后腿肌+背腰肌)重量无显著影响(P>0.05)。短期限饲显著降低了血浆中甘油三酯(TG)和极低密度脂蛋白(VLDL)含量(P<0.05),对肝脏和背腰肌中TG含量的影响不显著(P>0.05)。肝脏中,短期限饲显著降低了脂肪酸合成酶(FAS) mRNA的相对表达量(P<0.05),显著上调了肉碱脂酰转移酶1(CPT1)、肉碱脂酰转移酶2(CPT2)、G蛋白偶联受体41(GPR41)、G蛋白偶联受体43(GPR43)、过氧化物酶体增殖物激活受体α(PPARα) mRNA的相对表达量(P<0.05);骨骼肌中,短期限饲显著上调了脂蛋白脂肪酶(LPL)、脂肪酸结合蛋白(FABP)、G PR41、G PR43 mRNA的相对表达量(P<0.05),显著下调了CPT2 mRNA的相对表达量(P<0.05),对CPT1、PPARα、脂肪酸转运蛋白(FATP) mRNA的相对表达量无显著影响(P>0.05)。由此得出,短期限饲抑制了家兔肝脏中脂质的合成和外运,促进了脂肪酸在肝脏中的氧化利用,GPR41、GPR43和PPARα参与此过程;短期限饲促进了家兔骨骼肌对脂肪酸的摄取和利用,GPR41和GPR43参与此过程。

This experiment was conducted to study the effects of short-term feed restriction on expression of lipid metabolism-related genes in liver and skeletal muscle of rabbits,and to expound the regulatory mechanism of lipid metabolism in rabbits under short-term feed restriction.Forty 40-day-old Hyla rabbits with similar weight and good body state were randomly divided into 2 groups(control group and feed restriction group)with 20 replicates(half male and half female) per group and 1 rabbit per replicate.The rabbits in the control group were fed ad libitum,while the rabbits in the feed restriction group were fed with restricted feeding(feeding amount was about 70% of control group).The test period was 5 days.The results showed that short-term feed restriction significantly reduced the liver index of rabbits(P < 0.05),and had a decreased tendency in hindleg muscle weight(P=0.074 3),but did not significantly affect the weights of foreleg muscle,dorsal lumbar muscle and total muscle(foreleg muscle+hindleg muscle+dorsal lumbar muscle)(P>0.05).The contents of triglyceride(TG) and very low density lipoprotein(VLDL) in plasma were significantly reduced by short-term feed restriction(P<0.05),but the content of TG in liver and dorsal lumbar muscle was not significantly reduced(P>0.05).In the liver,the mRNA relative expression level of fatty acid synthase(FAS) was significantly down-regulated by short-term feed restriction(P<0.05),and the mRNA relative expression levels of carnitine acyl transferase 1(CPT1),carnitine acyl transferase 2(CPT2),G-protein-coupled receptor 41(GPR41),G-protein-coupled receptor 43(GPR43) and peroxisome proliferators activate receptor α(PPARα) were significantly up-regulated by short-term feed restriction(P<0.05).In the skeletal muscle,the mRNA relative expression levels of lipoprotein lipase(LPL),fatty acid binding protein(FABP),GPR41 and GPR43 were significantly up-regulated by short-term feed restriction(P<0.05),the mRNA relative expression levels of CPT2 was significantly up-regulated(P<0.05) by short-term feed restriction,and the mRNA relative expression levels of CPT1,PPARα and fatty acid transporters(FATP) were not significantly influenced by short-term feed restriction(P>0.05).In conclusion,short-term feed restriction inhibits lipid synthesis and output,and promotes the oxidation utilization of fatty acids in the liver,and GPR41,GPR43 and PPARα involved in this process;short-term feed restriction promotes the uptake and utilization of fatty acids in skeletal muscles,and GPR41 and GPR43 involved in this process.