Proteomics analysis of mitochondrial extract from liver of female zebrafish undergoing starvation and refeeding

Many fish species can withstand long period of food deprivation and consequently compensate for any weight loss by undergoing rapid growth during resumption of feeding. There is an interest in taking advantage of compensatory growth to reduce feed cost. In this present study, we attempted to compare the changes in hepatic mitochondrial proteome of zebrafish undergoing starvation and refeeding. Two‐dimensional gel separation and image analysis revealed a total of 65 spots that showed changes in expression after 15 days of starvation followed by 7 days of refeeding. A total of 35 proteins were selected for mass spectrometry analysis, resulting in the positive identification of 18 proteins. Identified proteins indicated that starvation resulted in reduction in glycolysis and increase in gluconeogenesis, while refeeding caused these activities to return to normal levels. Expression pattern of several proteins related to fatty acid and amino acid metabolism also suggested the utilization of non‐carbohydrate resources for energy during starving conditions. Proteins with chaperoning and antioxidative roles such as glucose‐regulated protein, paraxonase and heat‐shock protein were also upregulated in starved conditions.     

The effect of temperature and dietary fat level on tissue lipid composition in Atlantic salmon (Salmo salar) fed wax ester‐rich oil from Calanus finmarchicus

Copepod oil (CO) from the marine zooplankton, Calanus finmarchicus, is a potential alternative to fish oils (FOs) for inclusion in aquafeeds. The oil is composed mainly of wax esters (WE) containing high levels of saturated fatty acids (SFAs) and monounsaturated fatty alcohols that are poorly digested by fish at low temperatures. Consequently, tissue lipid compositions may be adversely affected in salmon‐fed CO at low temperatures. This study examined the lipid and FA compositions of muscle and liver of Atlantic salmon reared at two temperatures (3 and 12 °C) and fed diets containing either FO or CO, supplying 50% of dietary lipid as WE, at two fat levels (～330 g kg^?1, high; ～180 g kg^?1, low). Fish were acclimatized to rearing temperature for 1 month and then fed one of four diets: high‐fat fish oil (HFFO), high‐fat Calanus oil (HFCO), low‐fat fish oil (LFFO) and low‐fat Calanus oil (LFCO). The fish were grown to produce an approximate doubling of initial weight at harvest (220 days at 3 °C and 67 days at 12 °C), and lipid content, lipid class composition and FA composition of liver and muscle were determined. The differences in tissue lipid composition between dietary groups were relatively small. The majority of FA in triacylglycerols (TAG) in both tissues were monounsaturated, and their levels were generally higher at 3 °C than 12 °C. Polyunsaturated fatty acids (PUFA), particularly (n‐3) PUFA, predominated in the polar lipids, and their level was not significantly affected by temperature. The PUFA content of TAG was highest (～26%) in the muscle of fish fed the HFCO diet at both temperatures. Tissue levels of SFAs were lower in fish‐fed diets containing HFCO than those fed HFFO, LFFO or LFCO, particularly at 3 °C. The results are consistent with Atlantic salmon being able to incorporate both the FA and fatty alcohol components of WE into tissue lipids but, overall, the effects of environmental temperature on tissue lipids were more pronounced in fish fed the CO diets than FO diets.     

哲罗鱼肝脏和胰脏发生和发育的组织学研究

采用形态观察与连续组织切片技术,观察和研究了哲罗鱼（Hucho tai men）肝脏和胰脏在胚胎期（水温7～8℃）和胚后期（水温3～14℃）的发育。结果表明,与大多数硬骨鱼类不同,哲罗鱼的肝脏是在破膜前就开始发生、发育,而胰脏是在破膜后出现,以后逐渐发育完善。受精18 d肝原基细胞出现,破膜8 d,胰细胞出现,破膜8 ...     

Interactive effect of two methyl‐group sources on the growth and phospholipids’ content of kuruma shrimp Marsupenaeus japonicus Bate post‐larvae

Six micro‐bound diets were formulated to contain three levels of choline chloride (CC) (0.0, 0.6 and 1.2 g kg⁻¹) and 2 levels of methionine (Met) (0 and 15 g kg⁻¹). Soybean protein isolates (SPI) were used as the main protein source for its limited Met content. A significant (P < 0.05) interaction was determined between CC and Met on the survival (S %), weight gain (WG%), specific growth rate (SGR % day⁻¹), feed efficiency ratio (FER), protein efficiency ratio (PER) and phosphatidylcholine (PC), phoshphatidylethanolamine (PE) and Met contents of the whole body of shrimp. The shrimp group did not receive either supplemental CC or Met showed lower (P < 0.05) values of the above‐mentioned parameters than other shrimp groups fed with 0.6 and 1.2 g kg⁻¹ supplemental CC with or without Met supplementation. The present study showed that supplementation of 1.2 g kg⁻¹ CC in the diets could compensate shrimp post‐larvae with the needed methyl group when received Met‐deficient diets. The study also assumed that the biosynthesis of PC in the shrimp’s body can be achieved by the methylation of PE through the S‐adenosylmethionine (SAM) pathway and/or through the cytosine di‐phosphoryl (CDP) choline pathway directly from dietary choline.     

Growth performance of the white shrimp,Litopenaeus vannamei,fed on practical diets with increasing levels of the Antarctic krill meal,Euphausia superba,reared in clear‐ versus green‐water culture tanks

Litopenaeus vannamei were stocked in 25 clear‐water 500‐L tanks at 100 shrimp m^?2 and in 25 green‐water 1000‐L tanks at 60 animals m^?2. Four diets were formulated to include krill meal at 10, 50 or 110 g kg^?1; or krill oil at 25 g kg^?1 by replacing fish meal, fish oil, soybean lecithin and cholesterol. Diets had similar levels of crude protein, total energy and essential amino acids. After 72 days, shrimp reared in clear and green water showed no differences in performance among diets. In clear water, shrimp attained 13.1 ± 0.59 g body weight, 1.00 ± 0.06 g week^?1 growth, 81.4 ± 7.3% survival, 780 ± 118 g m^?2 yield, 16.9 ± 1.8 g shrimp^?1 apparent feed intake (AFI), and 2.18 ± 0.29 food conversion ratio (FCR). In green water, shrimp attained 14.3 ± 0.81 g body weight, 1.04 ± 0.09 g week^?1 growth, 91.4 ± 5.4% survival, 569 ± 69 g m^?2 yield, 20.9 ± 3.2 g shrimp^?1 AFI, and 2.22 ± 0.34 FCR. Diets containing krill meal or krill oil were able to fully replace the protein and lipid value of fish meal, fish oil, soybean lecithin and cholesterol at no cost to performance.     

月桂酸单甘油酯对花鲈脂质代谢的影响

为评价月桂酸单甘油酯(Glycerol monolaurate,GML)对花鲈(Lateolabrax maculatus)脂质代谢的影响,文章通过基础饲料拌喂0 mg·kg^-1(对照组)、1000 mg·kg^-1(低剂量组)、2000 mg·kg^-1(中剂量组)和4000 mg·kg^-1(高剂量组)的GML,养殖均质量为(230±20)g的花鲈8周。结果显示:1)添加GML组的腹脂率均显著降低,肝体比第4周明显降低(P<0.05);2)低剂量和中剂量组的血清甘油三酯、总胆固醇、低密度脂蛋白胆固醇浓度和天冬氨酸转氨酶活性均低于高剂量组(P<0.05);3)中剂量组的高密度脂蛋白胆固醇浓度均高于其他组(P<0.05);4)添加GML组肝脏中超氧化物歧化酶、谷胱甘肽过氧化物酶活性和还原型谷胱甘肽浓度均有升高,而丙二醛浓度显著降低(P<0.05);5)添加GML组的肝脏中脂肪酸合成酶和乙酰辅酶A羧化酶活性降低,且脂质沉积明显减少(P<0.05);脂蛋白脂酶活性均显著下降,中剂量组显著高于其他组(P<0.05)。综上,饲料中添加GML能够显著改善花鲈脂质代谢,该实验条件下,GML最适拌料量为2000 mg·kg^-1。     

不同植物油对大规格吉富罗非鱼生长性能、组织脂肪酸组成的影响

本试验旨在探究大规格吉富罗非鱼(GIFT)对不同植物油的利用效果,筛选出大规格吉富罗非鱼饲料中合适的植物脂肪源。分别以大豆油(SO)、棕榈油(PO)、棉籽油(CO)、菜籽油(RO)、磷脂油(SL)和大豆油∶棕榈油∶棉籽油∶菜籽油∶磷脂油=1∶1∶1∶1∶1的混合油(MIX)为脂肪源配制6种等氮等脂的试验饲料,饲喂初始体重为(229.92±0.31)g的吉富罗非鱼8周。每种试验饲料投喂4个网箱(重复),每个网箱放养50尾。结果表明:对于增重率和特定生长率,棉籽油组和混合油组显著低于菜籽油组(P0.05)。菜籽油组饲料系数显著低于混合油组(P0.05),其他各组间无显著差异(P0.05)。混合油组蛋白质效率显著低于菜籽油组和磷脂油组(P0.05)。混合油组肝体指数显著高于棕榈油组和菜籽油组(P0.05)。大豆油组、菜籽油组、棕榈油组和磷脂油组在增重率、特定生长率和饲料系数方面没有显著差异(P0.05)。大豆油组和菜籽油组肌肉饱和脂肪酸总量显著低于其他各组(P0.05)。对于肌肉中n-3系脂肪酸/n-6系脂肪酸,菜籽油组显著高于其他各组(P0.05),棉籽油显著低于其他各组(P0.05)。棉籽油组肝脏饱和脂肪酸总量显著高于其他各组(P0.05),菜籽油组则显著低于其他各组(P0.05);对于肝脏n-3/n-6,菜籽油组显著高于其他各组(P0.05)。各组肌肉脂肪酸组成与饲料脂肪酸组成的相关系数均高于肝脏脂肪酸组成与饲料脂肪酸组成的相关系数。在饲料脂肪酸组成与肌肉或肝脏脂肪酸组成的相关系数中,均以棕榈油组最大,磷脂油组最小。由此得出,大豆油、棕榈油、菜籽油和磷脂油可以作为大规格吉富罗非鱼(体重为230~790 g)饲料中良好的脂肪源。大规格吉富罗非鱼肌肉中脂肪酸组成一定程度上被饲料脂肪酸组成影响,但肝脏脂肪酸组成与饲料脂肪酸组成的相关性较小。     

驼背鲈肝脏结构的光镜和透射电镜观察

采用HE、Mallory氏三色法、Heidenhain氏Azan染色,PAS反应,组织块银浸染方法,对组织切片染色处理,应用光学显微镜和透射电镜对驼背鲈肝脏的显微和超微结构进行了观察,结果表明驼背鲈肝组织中肝细胞界限不明显,不存在双核现象,有暗细胞和亮细胞之分,胞质中细胞器丰富,有大量的线粒体、内质网和溶酶体,高尔基体很难观察到,仅在胆小管和狄氏间隙的附近发现。此外,在肝血窦的附近观察到成纤维细胞、枯否氏细胞和贮脂细胞。肝组织中胆管数量众多包括肝叶中央胆管、支胆管、小叶间胆管和小叶内胆管,并且在中央静脉附近偶见辐射状排列的肝细胞索。     

Mechanism of Fuzilizhong decoction alleviating inflammatory damage of rats with non-alcoholic fatty liver disease

AIM To observe the effect of Fuzilizhong decoction on the inflammatory damage of non-alcoholic fatty liver disease （NAFLD） rats and to explore its mechanism. METHODS SPF male SD rats were randomly divided into 6 groups： control group, model group, high dose （20 mg·kg^-1·d^-1）, middle dose （10 mg·kg^-1·d^-1）, low dose （5 mg·kg^-1·d^-1） Fuzilizhong decoction group and Yishanfu （30 mg·kg^-1·d^-1）group, 8 rats in each group. A NAFLD rat modelwas established by intragastric administration of fat emulsion for 4 weeks. Then the drug was given for 4 weeks in each treatment group. HE staining was performed to observe the histopathological changes of the rat liver.The serum levels of interleukin-2（IL-2）, IL-6 and tumor necrosis factor-α（TNF-α） were measured by ELISA. The expression of toll like receptor 4（TLR4） and NF-κB p65 in liver tissues at mRNA and protein levels was determined by RT-qPCR and Western bolt,respectively. RESULTS Compared with control group, the inflammatory damage of liver tissue was more serious, the serum levels of IL-2, IL-6 and TNF-α, the mRNA expression TLR4 and NF-κB p65 in liver tissues were significantly increased in model group（P<0.05）. However, compared with model group, the liver pathological changes in each treatment group were significantly relieved, the serum levels of IL-2, IL-6 and TNF-α, the mRNA expression of TLR4 and NF-κB p65 in liver tissues were significantly reduced（P<0.05）.In addition, the changes of TLR4 and p-NF-κB p65 protein levels in liver tissue were consistent with the changes of TLR4 and NF-κB p65 mRNA. CONCLUSION Fuzilizhong decoction attenuates the inflammatory damages of NAFLD in rats by inhibiting TLR4/NF-κB p65 signaling pathway.