title: Dietary L-carnitine supplementation increases lipid deposition in the liver and muscle of yellow catfish (Pelteobagrus fulvidraco) through changes in lipid metabolism.
abstract: Carnitine has been reported to improve growth performance and reduce body lipid content in fish. Thus, we hypothesised that carnitine supplementation can improve growth performance and reduce lipid content in the liver and muscle of yellow catfish (Pelteobagrus fulvidraco), a commonly cultured freshwater fish in inland China, and tested this hypothesis in the present study. Diets containing l-carnitine at three different concentrations of 47 mg/kg (control, without extra carnitine addition), 331 mg/kg (low carnitine) and 3495 mg/kg (high carnitine) diet were fed to yellow catfish for 8 weeks. The low-carnitine diet significantly improved weight gain (WG) and reduced the feed conversion ratio (FCR). In contrast, the high-carnitine diet did not affect WG and FCR. Compared with the control diet, the low-carnitine and high-carnitine diets increased lipid and carnitine contents in the liver and muscle. The increased lipid content in the liver could be attributed to the up-regulation of the mRNA levels of SREBP, PPARγ, fatty acid synthase (FAS) and ACCa and the increased activities of lipogenic enzymes (such as FAS, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and malic enzyme) and to the down-regulation of the mRNA levels of the lipolytic gene CPT1A. The increased lipid content in muscle could be attributed to the down-regulation of the mRNA levels of the lipolytic genes CPT1A and ATGL and the increased activity of lipoprotein lipase. In conclusion, in contrast to our hypothesis, dietary carnitine supplementation increased body lipid content in yellow catfish.
authors.affiliation: Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University,Wuhan430070,People's Republic of China.
authors.forename: Jia-Lang
authors.initials: JL
authors.lastname: Zheng
authors.affiliation: Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University,Wuhan430070,People's Republic of China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Luo
authors.affiliation: Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University,Wuhan430070,People's Republic of China.
authors.forename: Mei-Qing
authors.initials: MQ
authors.lastname: Zhuo
authors.affiliation: Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University,Wuhan430070,People's Republic of China.
authors.forename: Ya-Xiong
authors.initials: YX
authors.lastname: Pan
authors.affiliation: Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University,Wuhan430070,People's Republic of China.
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Song
authors.affiliation: Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University,Wuhan430070,People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Hu
authors.affiliation: Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University,Wuhan430070,People's Republic of China.
authors.forename: Qi-Liang
authors.initials: QL
authors.lastname: Chen
mesh_terms: D000818:Animals; D002331:Carnitine / Q000008:administration & dosage* / Q000032:analysis; D002397:Catfishes / Q000378:metabolism*; D002681:China; D019587:Dietary Supplements; D064429:Fatty Acid Synthases / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D050356:Lipid Metabolism / Q000187:drug effects*; D008055:Lipids / Q000032:analysis; D050155:Lipogenesis / Q000235:genetics; D008066:Lipolysis / Q000235:genetics; D008099:Liver / Q000737:chemistry / Q000378:metabolism*; D009132:Muscles / Q000737:chemistry / Q000378:metabolism*; D047495:PPAR gamma / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D051779:Sterol Regulatory Element Binding Proteins / Q000235:genetics
chemical_list: D008055:Lipids; D047495:PPAR gamma; D012333:RNA, Messenger; D051779:Sterol Regulatory Element Binding Proteins; D064429:Fatty Acid Synthases; D002331:Carnitine