title: Differential effects of acute and chronic zinc (Zn) exposure on hepatic lipid deposition and metabolism in yellow catfish Pelteobagrus fulvidraco.
abstract: The present study is conducted to determine the potential mechanisms of Zn on hepatic lipid deposition and metabolism for yellow catfish Pelteobagrus fulvidraco with 8-week chronic exposure to low Zn levels (Zn levels: 0.05, 0.35 and 0.86mg/l Zn, respectively) and 96-h acute exposure to a high Zn level (Zn level: 4.71mg/l Zn, respectively). For that purpose, hepatic lipid deposition and Zn accumulation, hepatic carnitine palmitoyltransferase I (CPT I) and lipoprotein lipase (LPL) activities, and the hepatic mRNA expression of ten genes involved in lipid metabolism are determined. Chronic (8 weeks) exposure to low Zn levels apparently increases hepatic lipid content, hepatosomatic index (HSI) (P<0.05) and LPL activity, and reduces hepatic CPT I activity. In contrast, the acute (96h) exposure to high Zn level reduces hepatic lipid content, HSI and LPL activity, and increases CPT I activity. The change of mRNA levels of genes related to lipid metabolism is Zn concentration-dependent. Pearson correlations among mRNA expression levels, lipid content, CPT I and LPL activities in liver are also observed in yellow catfish with the 8-week chronic Zn exposure. For the first time, our study demonstrates the effect of waterborne Zn exposure on lipid metabolism at the molecular levels in fish, which may contribute to understanding the mechanism of Zn-induced hepatic toxicity in fish.
authors.affiliation: Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture of P.R.C., Fishery College, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jia-Lang
authors.initials: JL
authors.lastname: Zheng
authors.forename: Zhi
authors.initials: Z
authors.lastname: Luo
authors.forename: Cai-Xia
authors.initials: CX
authors.lastname: Liu
authors.forename: Qi-Liang
authors.initials: QL
authors.lastname: Chen
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: Tan
authors.forename: Qing-Ling
authors.initials: QL
authors.lastname: Zhu
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gong
mesh_terms: D000818:Animals; D002397:Catfishes / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000032:analysis; D004781:Environmental Exposure; D005786:Gene Expression Regulation; D050356:Lipid Metabolism / Q000187:drug effects*; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D017422:Sequence Analysis, DNA / Q000662:veterinary; D013054:Spectrophotometry, Atomic / Q000662:veterinary; D015032:Zinc / Q000378:metabolism / Q000633:toxicity*
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D015032:Zinc