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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.
The effect of dietary n−3 and n−6 polyunsaturated fatty acids (PUFAs) on juvenile Arctic charr Salvelinus alpinus (L.) were investigated with respect to essential fatty acid (EFA) deficiency and lipid metabolism using one commercial and
12 casein-based test diets. Arctic charr with mean weight of 1.6g were fed test diets for 12 weeks at 10°C. At the end of
the feeding, blood, liver, muscle and whole fish were sampled to determine haematocrit, haemoglobin, water content, lipid
and fatty acid composition. Charr fed diets containing 0–1.0% n−3 PUFAs showed typical EFA deficiency signs: fatty liver or
elevated water content in whole body or substantial accumulation of 20:3n−9 in liver polar lipids. These signs were less apparent
or disappeared when charr were fed diets containing ≥ 2.0% 18:3n−3. No correlation was found between dietary PUFAs and haematocrit
or haemoglobin values. Significant changes in fatty acid composition of liver polar lipids in charr fed dietary PUFAs indicate
that charr can convert 18:3n−3, 18:2n−6 and 20:5n−3 into long-chain PUFAs. While charr had a direct incorporation of dietary
22:6n−3 into liver and muscle there appears to be preferential utilization of n−3 PUFAs for elongation and desaturation. The
conversion of 18:4n−3 was less in muscle than in livers. These findings, combined with data on growth and feed efficiency
reported previously by Yang and Dick (1993), indicate that charr require 1−2% dietary 18:3n−3 (dry weight). Small amounts
of dietary 18:2n−6 (up to 0.7%) did not have detrimental effects on charr. 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.
E. HENROTTE D. KPOGUE S.N.M. MANDIKI N. WANG J. DOUXFILS J. DICK D. TOCHER P. KESTEMONT 《Aquaculture Nutrition》2011,17(2):e216-e225
The aim of this work was to study the fatty acid (FA) bioconversion ability in Eurasian perch fed with diets differing in their polyunsaturated fatty acids (PUFA) from n‐3 and n‐6 series content at two development stages: adults in exogenous vitellogenesis, and juveniles during the on‐growing phase. Duplicate groups of adults and juveniles were fed for 12 weeks with four diets: D1 and D2, two diets prepared with fish oil partially or totally as the lipid source, and so containing long‐chain PUFA (LC‐PUFA). Those two diets differed by their n‐3/n‐6 FA dietary ratio (0.2 and 7.0, respectively), D1 being characterized by a high n‐6 LC‐PUFA level, while D2 had a high level of n‐3 LC‐PUFA. D3 and D4 were constituted only with vegetable oils, and were therefore devoid of LC‐PUFA. D3 was characterized by a high level of 18:2 n‐6 (n‐6/n‐3 ratio of 0.3), while D4 was characterized by a high level of 18:3 n‐3 (n‐3/n‐6 ratio of 1.9). Both groups of fish were able to elongate and desaturate the 18:3 n‐3 precursor into eicosapentaenoic acid and docosahexaenoic acid, regarding the FA profile of livers. Furthermore, total elongation/desaturation from [1‐14C]18:3 n‐3 of LC‐PUFA was higher in fish fed with the high dietary 18:3 n‐3 level compared to the diet rich in n‐3 LC‐PUFA. By opposition, the bioconversion of 18:2 n‐6 into LC‐PUFA was limited, regarding the elongation/desaturation activity of LC‐PUFA from [1‐14C]18:2 n‐6. In view of the great ability for bioconversion of n‐3 FA, linseed oil is a promising alternative to fish oil in formulating feed for juveniles perch as there were no differences in terms of specific growth rate between the treatments, but adults undergoing maturation should have at least partially LC‐PUFA in their diet, particularly arachidonic acid (ARA) which is important during maturation, as breeders are not able to bioconvert 18:2 n‐6 into ARA. 相似文献
5.
Ernest L Burdge 《Pest management science》2000,56(3):245-248
RH‐1965 is a new bleaching herbicide which causes newly developing leaf tissue to emerge devoid of photosynthetic pigments. Mode‐of‐action studies revealed that RH‐1965 inhibited the accumulation of both total chlorophyll and β‐carotene. Concomitantly, it induced the accumulation of the β‐carotene precursors, phytoene, phytofluene and, in particular, ξ‐carotene. Inhibition of chlorophyll accumulation by RH‐1965 is attributed to the photo‐oxidative destruction of chlorophyll in the absence of β‐carotene because RH‐1965 blocked chlorophyll accumulation to a greater extent under high light (50–330 µE m−2 s−1) than under low light (0.8 µE m−2 s−1) conditions. Radish (Raphanus sativus L) and barnyardgrass (Echinochloa crus‐galli (L) Beauv) were very senstive to RH‐1965. Under high light (330 µE m−2 s−1), the I50 values for inhibition of chlorophyll accumulation were 0.10 and 0.15 µM , respectively. Wheat (Triticum aestivus L), on the other hand, was much less sensitive to RH‐1965 (I50 = 1.4 µM ). It is concluded that the mode of action of RH‐1965 involves the inhibition of ξ‐carotene desaturation. © 2000 Society of Chemical Industry 相似文献
6.
Arctic charr,Salvelinus alpinus L. were fed five test diets containing 0% or 1% of different polyunsaturated fatty acids (PUFA) for 93 days. The fish were injected intraperitoneally with (1–14C)–18:2(n–6) or (1–14C)–18:3(n–3), and the bioconversion to longer chain PUFA studied. The conversion rate in neutral lipids was slow, with most label found as the fatty acid injected, while extensive modification took place prior to or during incorporation into polar lipids. Linolenic acid was preferred over linoleic acid as substrate for elongation and desaturation regardless of diet. In polar lipids, the predominant products of (1–14C)–18:2(n–6) metabolism were generally 20:3(n–6) and 20:4(n–6), while 18:4(n–3), 20:5(n–3) and 22:6(n–3) were the major products of (1–14C)–18:3(n–3) metabolism. The lack of radioactivity in 22:5(n–6) suggests that 4 desaturation is specific for (n–3) PUFA. Feeding the PUFA deficient diet reduced the 5 desaturation compared to fish maintained on PUFA supplemented diets. The 6 desaturation was only reduced in fish fed C18 PUFA and injected with (1–14C)–18:3(n–3). Longer chain C20 and C22 PUFA, particularly those of the (n–3) family, exerted some inhibition on the elongation and desaturation of injected fatty acids compared to those fed C18 PUFA. The incorporation of radiolabelled fatty acids into polar lipids of fish fed a commercial diet was very low, and the desaturation neglectible in both polar and neutral lipids, showing that Arctic charr under culture conditions do not convert short chain PUFA to longer chain metabolites. 相似文献
7.
B. Ruyter C. Røsjø K. Måsøval O. Einen M.S. Thomassen 《Fish physiology and biochemistry》2000,23(2):151-158
Atlantic salmon (Salmo salar) were fed diets containing fish oil supplemented with 22:6n-3 (FO diet) or linseed oil supplemented with 20:5n-3 (LO diet) for 6
months. The effects of these diets, both containing about 36% n-3 fatty acids, on the esterification, desaturation and elongation of [1-14C] 18:2n-6 and [1-14C] 18:3n-3 were investigated in isolated hepatocytes. The percentages of radioactivity which was esterified from [1-14C] 18:2n-6 or [1-14C]18:3n-3 into total lipids, were approximately 20% lower in hepatocytes from fish fed the FO diet than in hepatocytes from fish fed the LO diet. The percentages of radioactivity esterified in both groups were further reduced when 0.1 mM unlabelled 22:6n-3 was added to the incubation. The percentage of desaturation and elongation products formed from [1-14C] 18:2n-6 was twice as high in hepatocytes from salmon fed the FO diet as it was in hepatocytes from fish fed the LO diet. The ratio of 18:2n-6 to 18:3n-3 was five times higher in the FO diet, and this probably promoted the conversion of 18:2n-6 to longer chain n-6 fatty acids. When 0.1mM unlabelled 22:6n-3 was added to the incubation medium, the percentages of desaturation and elongation products formed were unchanged. Thus, a high level of 22:6n-3 in the diet is apparently not inhibiting the conversion of 18:2n-6 to 20:4n-6, as long as the amount of 18:2n-6 present is substantially higher than that of 18:3n-3. No desaturation and elongation products were recovered from the phospholipids of hepatocytes incubated with [1-14C] 18:3n-3 in any of the groups. However, the `dead end' elongation product 20:3n-3 was found in the triacylglycerol fraction, and the percentage of this fatty acid increased when 22:6n-3 was added to the incubation medium. 相似文献
8.
Johnson LR Drazenovich TL 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2007,21(2):219-225
BACKGROUND: Bronchoscopy is an important tool for identifying an underlying etiology for respiratory disease in cats. However, the procedure is challenging, because feline airways are small and prone to bronchoconstriction. HYPOTHESIS: Bronchoscopy and bronchoalveolar lavage (BAL) are appropriate and safe diagnostic procedures in the cat. ANIMALS: Sixty-eight cats. METHODS: Flexible bronchoscopy was performed in all cats with the cats under propofol infusion with jet ventilation. The procedures were reviewed for BAL volumes instilled and recovered and for the number and type of complications with the use of 3 flexible endoscopes < 5.0-mm outer diameter. The BAL procedure was compared among scopes by using a one-way analysis of variance. Complication rates were compared by using chi-square analysis. Significance was set at P < .05. RESULTS: Clinical diagnoses included inflammatory airway disease in 46 of 68 cats, pneumonia in 10 of 68, neoplastic disease in 8 of 68, and other conditions in 4 of 68 cats. Mean lavage volumes instilled for the 3 scopes were 2.62-5.05 mL/kg (range, 0.77-9.38 mL/kg). Mean percent fluid recovered for the 3 scopes was 51-73%, (range, 0-140%). BAL cell counts were adequate for cytologic assessment (> 300 cells/microL) in 61 of 64 cats (97%), and in 107 of 120 samples (89%) collected. Complications occurred in 38% of procedures; however, these were mild in 24% of cats; 6% of cats died or were euthanized after the procedure. Complications were not associated with fluid volume instilled or recovered, and could not be related to the underlying disease process. CONCLUSIONS AND CLINICAL IMPORTANCE: Flexible bronchoscopy with BAL was well tolerated in most cats examined. 相似文献
9.
植物脂肪酸不饱和性对植物抗寒性影响的研究 总被引：3，自引：0，他引：3
对植物脂肪酸不饱和性与植物抗寒性关系、催化不饱和脂肪酸形成的酶特性和转化膜质脱饱和酶和酰基转移酶基因提高植物抗寒性的研究进展进行了分析论述。膜是植物低温伤害的首要发生地,细胞膜的稳定性主要决定于膜质脂肪酸不饱和性,不饱和度越高,膜稳定性越强,抗寒性越强。膜质脂肪酸不饱和度主要由膜质脱饱和酶活性和酰基转移酶的特异性不同所致,目前克隆和研究了10多个与植物细胞膜质不饱和性相关的基因,通过高效表达这些基因可以明显提高冷敏感植物的抗寒性。因此转化膜脂不饱和脂肪酸合成酶基因是提高植物抗寒性的重要途径之一。通过分析近年来的研究进展认为,今后植物脂肪酸不饱和性的研究应向农业生产应用转化,同时要加强脂肪酸脱饱和酶表达调控的研究。 相似文献
10.
Crystalyn Legg-St. Pierre Isabelle Desprez Stephanie Chang Karen Machin Barbara Ambros 《Veterinary anaesthesia and analgesia》2021,48(4):524-531
ObjectiveTo evaluate the time to hemoglobin oxygen desaturation in chickens (Gallus gallus domesticus) with and without preoxygenation before isoflurane induction of anesthesia and rocuronium-induced apnea.Study designProspective, randomized crossover study.AnimalsA total of 10 healthy adult Lohmann Brown-Lite hens.MethodsHens were anesthetized with isoflurane for intravenous (IV) and intraarterial catheter placement and allowed to fully recover from anesthesia. Hens in the preoxygenation treatment were administered oxygen (2 L minute–1) via a facemask for 3 minutes prior to induction of anesthesia with 3% isoflurane in oxygen. In the alternative treatment, hens were not preoxygenated prior to induction of anesthesia with isoflurane in oxygen. Apnea was then induced with rocuronium bromide (1.0 mg kg–1) administered IV, and anesthesia was maintained with IV propofol infusion. A cloacal pulse oximeter measured hemoglobin oxygen saturation (SpO2). Time was recorded from the start of apnea until SpO2 was 90% (desaturation). The trachea was intubated, and anesthesia was maintained with isoflurane in oxygen with manual ventilation until spontaneous breathing returned and SpO2 ≥ 99%. PaO2 was measured before each treatment, after preoxygenation, postinduction and at desaturation. Data were analyzed between treatments using Wilcoxon matched-pairs signed rank tests with Holm-?idák multiple comparison test, and within treatments using Friedman test with Dunn’s multiple comparison test (p < 0.05). Data are reported as median (range).ResultsTime from start of apnea until hemoglobin desaturation was not significantly different between preoxygenated and nonpreoxygenated hens [26.5 (16–50) seconds and 24.0 (5–57) seconds, respectively; p = 0.25]. No differences in PaO2 between treatments were observed at any time point.Conclusions and clinical relevancePreoxygenation for 3 minutes before isoflurane mask induction of anesthesia and apnea does not significantly increase time until desaturation in hens. 相似文献