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1.
J. FONSECA-MADRIGAL V. KARALAZOS P.J. CAMPBELL J.G. BELL & D.R. TOCHER 《Aquaculture Nutrition》2005,11(4):241-250
This study aimed to investigate the effects of dietary crude palm oil (CPO) on fatty acid metabolism in liver and intestine of rainbow trout. Triplicate groups of rainbow trout for 10 weeks at 13 °C were fed on diets in which CPO replaced fish oil (FO) in a graded manner (0–100%). At the end of the trial, fatty acid compositions of flesh, liver and pyloric caeca were determined and highly unsaturated fatty acid (HUFA) synthesis and fatty acid oxidation were estimated in isolated hepatocytes and caecal enterocytes using [1‐14C]18:3n‐3 as substrate. Growth performance and feed efficiency were unaffected by dietary CPO. Fatty acid compositions of selected tissues reflected the dietary fatty acid composition with increasing CPO resulting in increased proportions of 18:1n‐9 and 18:2n‐6 and decreased proportions of n‐3HUFA, 20:5n‐3 and 22:6n‐3. Palmitic acid, 16:0, was also increased in flesh and pyloric caeca, but not in liver. The capacity of HUFA synthesis from 18:3n‐3 increased by up to threefold in both hepatocytes and enterocytes in response to graded increases in dietary CPO. In contrast, oxidation of 18:3n‐3 was unaffected by dietary CPO in hepatocytes and reduced by high levels of dietary CPO in enterocytes. The results of this study suggest that CPO can be used at least to partially replace FO in diets for rainbow trout in terms of permitting similar growth and feed conversion, and having no major detrimental effects on lipid and fatty acid metabolism, although flesh fatty acid compositions are significantly affected at an inclusion level above 50%, with n‐3HUFA reduced by up to 40%. 相似文献
2.
Effects of dietary lipid level and vegetable oil on fatty acid metabolism in Atlantic salmon (Salmo salar L.) over the whole production cycle 总被引：1，自引：0，他引：1
D.R. Tocher J.G. Bell F. McGhee J.R. Dick J. Fonseca-Madrigal 《Fish physiology and biochemistry》2003,29(3):193-209
Changes in fatty acid metabolism in Atlantic salmon (Salmo salar) induced by vegetable oil (VO) replacement of fish oil (FO) and high dietary oil in aquaculture diets can have negative impacts
on the nutritional quality of the product for the human consumer, including altered flesh fatty acid composition and lipid
content. A dietary trial was designed to investigate the twin problems of FO replacement and high energy diets in salmon throughout
the entire production cycle. Salmon were grown from first feeding to around 2 kg on diets in which FO was completely replaced
by a 1:1 blend of linseed and rapeseed oils at low (14–17%) and high (25–35%) dietary oil levels. This paper reports specifically
on the influence of diet on various aspects of fatty acid metabolism. Fatty acid compositions of liver, intestinal tissue
and gill were altered by the diets with increased proportions of C18 polyunsaturated fatty acids and decreased proportions of n-3 highly unsaturated fatty acids (HUFA) in fish fed VO compared
to fish fed FO. HUFA synthesis in hepatocytes and enterocytes was significantly higher in fish fed VO, whereas β-oxidation
was unaltered by either dietary oil content or type. Over the entire production cycle, HUFA synthesis in hepatocytes showed
a decreasing trend with age interrupted by a large peak in activity at seawater transfer. Gill cell prostaglandin (PG) production
showed a possible seasonal trend, with peak activities in winter and low activities in summer and at seawater transfer. PG
production in seawater was lower in fish fed the high oil diets with the lowest PG production generally observed in fish fed
high VO. The changes in fatty acid metabolism induced by high dietary oil and VO replacement contribute to altered flesh lipid
content and fatty acid compositions, and so merit continued investigation to minimize any negative impacts that sustainable,
environmentally-friendly and cost-effective aquaculture diets could have in the future.
Abbreviations: FO - fish oil; HUFA - highly unsaturated fatty acids acids (carbon chain length ≥C
20 with ≥3 double bonds); LO - linseed oil; RO - rapeseed oil; VO - vegetable oil.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
The static or declining supply of fish oil from industrial fisheries demands the search of alternatives, such as plant (vegetable)
oils, for diets in expanding marine aquaculture. Vegetable oils are rich in C18 polyunsaturated fatty acids but devoid of the n-3 highly unsaturated fatty acids in fish oils. Previous studies, primarily
with salmonids, have shown that including vegetable oils in their diets increased hepatocyte fatty acid desaturation. In the
present study, we have investigated the effects of dietary partial substitution of fish oil (FO) with rapeseed oil (RO), linseed
oil (LO) and olive oil (OO) on the desaturation /elongation and, -oxidation capacities of [1-14C]18:3n-3 in isolated hepatocytes from European sea bass (Dicentrarchus labrax L.), in a simultaneous combined assay. Fish were fed during 34 weeks with diets containing 100% FO, or RO, LO and OO, each
included at 60% with the balance being met by FO, with no detrimental effect upon growth or survival. The highest total desaturation
rates were found in hepatocytes of fish fed FO diet (0.52±0.08 pmol/h/mg protein) and OO diet (0.43±0.09 pmol/h/mg protein),
which represented 3.2% and 2.7% of total [1-14C]18:3n-3 incorporated, respectively. In contrast, lowest desaturation rates were presented by hepatocytes of fish fed LO
and RO diets (0.23±0.06 and 0.14±0.05 pmol/h/mg protein, respectively) represented 1.4% and 0.9% of total [1-14C]18:3n-3 incorporated, respectively. The rates of [1-14C]18:3n-3 β-oxidized were between 11-fold and 35-fold higher than desaturation. However, no significant differences were observed
among β-oxidation activities in hepatocytes of fish fed any of the diets. The present study demonstrated that the European
sea bass, as a carnivorous marine fish, presented a ‘marine’ fish pattern in the metabolism of 18:3n-3 to 20:5n-3 and 22:6n-3.
This species appeared to have all the enzymic activities necessary to produce 22:6n-3 but presented only extremely low rates
of fatty acid bioconversion. Furthermore, nutritional regulation of hepatocyte fatty acid desaturation was minimal, and dietary
vegetable oils did not increase desaturase activities, and in RO and LO treatments the activity was significantly lower.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
4.
Savlík M Polácková L Szotáková B Lamka J Velík J Skálová L 《Research in veterinary science》2007,83(1):20-26
Basal activities of certain pheasant hepatic and intestinal biotransformation enzymes and modulation of their activities by anthelmintics flubendazole (FLBZ) and mebendazole (MBZ) were investigated in subcellular fractions that were prepared from liver and small intestine of control and FLBZ or MBZ treated birds. Several oxidation, reduction and conjugation enzyme activities were assessed. In the liver, treatment of pheasants by FLBZ or MBZ caused very slight or no changes in monooxygenase activities and conjugation enzymes. More significative changes were detected in small intestine. Metyrapone and daunorubicin reductase activities were increased by both substances in the liver. This is the first evidence that certain benzimidazoles modulate reductases of carbonyl group. With respect to the relatively slight extent of the changes caused by FLBZ or MBZ we can assume that repeated administration of therapeutic doses of both FLBZ and MBZ has probably no serious influence on pheasant biotransformation enzyme system. 相似文献
5.
采用胶原酶消化法分离猪皮下前脂肪细胞,以含50 nmol/L胰岛素、100 nmol/L地塞米松、0.25 mmol/L 3-异丁基-1-甲基黄嘌呤、100 nmol/L罗格列酮的分化培养液对前脂肪细胞进行诱导分化,借助实时定量RT-PCR方法检测了PPARγ、DECR1和ECHS1 3基因的表达模式,结果发现:PPARγ、DECR1和ECHS1 3基因均于诱导分化后48 h达到表达高峰,此时的表达量分别是诱导前的93.0,5.4和7.8倍;PPARγ同DECR1和ECHS1两基因表达量变化趋势间的相关系数分别为0.92和0.97,DECR1同ECHS1的相关系数为0.94,均达到极显著相关(P<0.01)。实验结果表明:前脂肪细胞在分化过程中细胞内脂肪酸生物合成和脂肪酸β-氧化同时发生,以维持细胞的稳态。 相似文献
6.
The prediction of the oxidation rate of elemental sulfur (S0) is a critical step in sulfur (S) fertilizer strategy to supply plant-available sulfur. An incubation experiment was conducted to determine the rate and amount of S0 oxidation in relation to the contribution of Thiobacillus spp. and aerobic heterotrophic S-oxidizing bacteria. After 84 days, 16.3% and 22.4% of the total S0 applied to the soil were oxidized at 20 and 30 ℃, respectively. The oxidation of S0 proved to be a two-step process with a rapid oxidation during the first 28 days and a slow oxidation from then on. The highest oxidation rate of 12.8 μg S cm-2 d-1 was measured during the first two weeks at 30 ℃. At 20 ℃ the highest oxidation rate of 10.2 μg S cm-2 d-1 was obtained from two to four weeks after start of the experiment. On an average the soil pH declined by 3.6 and 4.0 units after two weeks of experiment. At the same time the electric conductivity increased nine times. With the oxidation of S0 the population of Thiobacillus spp. and aerobic heterotrophic S-oxidizing bacteria increased. The corresponding values for Thiobacillus spp. and aerobic heterotrophic S-oxidizing bacteria increased from 2.9 × 105 and 1.4 × 105 g-1 soil at the start of the experiment to 4 × 108 and 5.6 × 108 g-1 soil 14 days after S0 application, respectively. No Thiobacillus spp. was present eight weeks after S0 application. The results suggested that oxidation of residual S0 completely relied on aerobic heterotrophic S-oxidizing bacteria. 相似文献
7.
Z.Y. DU P. CLOUET L.M. HUANG P. DEGRACE W.H. ZHENG J.G. HE L.X. TIAN & Y.J. LIU 《Aquaculture Nutrition》2008,14(1):77-92
Herbivorous grass carp (Ctenopharyngodon idella) has been reported to exhibit low capacity to utilize high dietary lipid, but different lipid sources might affect this limited capacity. In order to compare the effects of different lipid sources with different lipid levels, juvenile grass carp were fed one of nine diets containing three oils [lard, plant oil mixed by maize and linseed oil, and n‐3 high unsaturated fatty acid‐enriched (HUFA‐enriched) fish oil] at three lipid levels (20, 60 and 100 g kg?1 dry diet) for 8 weeks. Decreased feed intake, poor growth performance, hepatic pathology and higher blood lipid peroxidation were found in 60 and 100 g kg?1 fish oil groups. Conversely, in lard and plant oil groups, even at 100 g kg?1 dietary lipid level, feed intake and growth performance did not decrease, despite histological observation revealed hepatic pathology in these groups. Plasma triglyceride and cholesterol contents increased significantly in all 100 g kg?1 dietary lipid groups. In the comparison of hepatic FA β‐oxidation among three oil groups at 60 g kg?1 dietary lipid level, impaired mitochondrial and peroxisomal FA oxidation capacity was observed in fish oil group. The results confirmed the relatively low capacity of grass carp to utilize high dietary lipid, and furthermore excess HUFA intake will result in more serious adverse effects than other FA. 相似文献
8.
The prediction of the oxidation rate of elemental sulfur (S 0 ) is a critical step in sulfur (S) fertilizer strategy to supply plant-available sulfur. An incubation experiment was conducted to determine the rate and amount of S 0 oxidation in relation to the contribution of Thiobacillus spp. and aerobic heterotrophic S-oxidizing bacteria. After 84 days, 16.3% and 22.4% of the total S 0 applied to the soil were oxidized at 20 and 30-C, respectively. The oxidation of S 0 proved to be a two-step process with a rapid oxidation during the first 28 days and a slow oxidation from then on. The highest oxidation rate of 12.8 μg S cm-2 d-1 was measured during the first two weeks at 30-C. At 20-C the highest oxidation rate of 10.2 μg S cm-2 d-1 was obtained from two to four weeks after start of the experiment. On an average the soil pH declined by 3.6 and 4.0 units after two weeks of experiment. At the same time the electric conductivity increased nine times. With the oxidation of S 0 the population of Thiobacillus spp. and aerobic heterotrophic S-oxidizing bacteria increased. The corresponding values for Thiobacillus spp. and aerobic heterotrophic S-oxidizing bacteria increased from 2.9 × 10 5 and 1.4 × 10 5 g-1 soil at the start of the experiment to 4 × 10 8 and 5.6 × 10 8 g-1 soil 14 days after S 0 application, respectively. No Thiobacillus spp. was present eight weeks after S 0 application. The results suggested that oxidation of residual S 0 completely relied on aerobic heterotrophic S-oxidizing bacteria. 相似文献
9.
Douglas R. Tocher Jorge Fonseca-Madrigal J. Gordon Bell James R. Dick R. James Henderson John R. Sargent 《Fish physiology and biochemistry》2002,26(2):157-170
We hypothesized that replacing fish oil with 18:3n-3-rich linseed oil may enable salmon to maintain the levels of tissue n-3HUFA
levels through a combination of increased desaturation activity and increased substrate fatty acid provision. To this end
we investigated desaturation/elongation of [1-14C18:3n-3 in hepatocytes and intestinal enterocytes, and determined the extent to which 18:3n-3 was oxidized and desaturated
by measuring both simultaneously in a combined assay. Salmon smolts were stocked randomly into five seawater pens and fed
for 40 weeks on diets in which the fish oil was replaced in a graded manner by linseed oil. At the end of the trial, fatty
acyl desaturation/elongation and oxidation activities were determined in isolated hepatocytes and intestinal enterocytes using
[1-14C]18:3n-3 as substrate, and samples of liver and intestinal tissue were collected for analysis of lipid and fatty acid composition.
The results showed that, despite increased desaturation of [1-14C]18:3n-3 in hepatocytes, provision of dietary 18:3n-3 did not prevent the decrease in tissue n-3HUFA in fish fed linseed
oil. Intestinal enterocytes were a site of significant fatty acid desaturation but, in contrast to hepatocytes, the activity
was not increased by feeding linseed oil and was generally lower in fish fed linseed oil compared to fish fed only fish oil.
In contrast, oxidation of [1-14C]18:3n-3 in enterocytes was generally increased in fish fed linseed oil compared to fish fed the diet containing only fish
oil. However, oxidation of [1-14C]18:3n-3 in hepatocytes was 4- to 8-fold lower than in enterocytes and was not affected by diet. Furthermore, oxidation of
[1-14C]18:3n-3 in enterocytes exceeded desaturation irrespective of dietary treatment, whereas similar amounts of [1-14C]18:3n-3 were desaturated and oxidized in hepatocytes from fish fed only fish oil and desaturation exceeded oxidation by
3-fold in fish fed the diet containing 100% linseed oil. The molecular mechanisms underpinning these results were discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
10.
U. Nordgarden B.E. Torstensen L. Frøyland T. Hansen & G.-I. Hemre 《Aquaculture Nutrition》2003,9(5):295-303
With the aim of elucidating seasonally changing lipid metabolism in immature Atlantic salmon (Salmo salar L.) in sea water, one group was reared under simulated natural light, while one group was reared under continuous light. Fatty acid profile in plasma lipoproteins did not vary during the experiment, while β‐oxidation capacity increased during spring, concurrent with decreasing temperatures. Simultaneously, the relative level of monounsaturated fatty acids (MUFA) in muscle tissue decreased (42–36%). Muscle levels of saturated fatty acids were low during early spring (19%), but then increased slowly, and muscle levels of polyunsaturated fatty acids increased during spring (from 36% to 39%). It is suggested that increased spring growth and the concomitant energy demand was met by increased lipid oxidation, where MUFA were preferred as energy substrate. 相似文献