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1.
We determined the effect of dietary arachidonic acid (20:4n-6, ARA) on tissue ratios of ARA/eicosapentaenoic acid (20:5n-3, EPA) and subsequent whole body production of the eicosanoids, prostaglandin F2α (PGF2α) and E2 (PGE2) in the marine larvae of striped trumpeter, Latris lineata. Larvae were also subjected to a hypersaline challenge (55 ppt) with an aim to determine possible relationships between tissue fatty acid profiles, prostanoid production, and their tolerance to osmotic challenge. From 5 to 23 days post-hatch (dph) larvae were fed live food, rotifers (Brachionus plicatilis), that had been enriched with one of five experimental emulsions containing increasing concentrations of ARA and constant EPA and 22:6n-3 (docosahexaenoic acid, DHA). Final ARA concentrations in the rotifers were 1.33, 3.57, 6.21, 8.21 and 11.22 mg g−1 DM. Larval growth and survival was unaffected by dietary ARA. Tissue fatty acid concentrations generally corresponded with dietary fatty acids and final tissue ratios of ARA/EPA ranged from 0.9 to 4.9. At 18 and 23 dph whole body concentrations of PGF2α and PGE2 generally increased as more dietary ARA was provided in a dose-response manner, and a significant elevation in both PGF2α and PGE2 in larvae fed the highest dietary ARA concentration was recorded at 23 dph compared to larvae receiving the lowest concentration. At 18 dph, the highest cumulative inactivity following a hypersaline challenge occurred in larvae fed 8.21 or 11.22 mg ARA g−1 DM, which was significantly greater than those receiving 3.57 mg ARA g−1 DM. At 23 dph no relationship between inactivity of larvae subjected to a hypersaline challenge to dietary ARA was evident. In summary, dietary ARA altered tissue ARA/EPA ratios, prostanoid production and resistance to a hypersaline challenge in larval striped trumpeter. While increasing dietary ARA generally resulted in elevation of prostanoids as well as increasing the number of inactive larvae following a hypersaline challenge at 18 dph, similar trends between prostanoids and larval inactivity were not evident at 23 dph, suggesting the exact mechanisms and relationships between eicosanoids and larval osmoregulation warrants further investigation. Nevertheless the study provides preliminary data on the effect of dietary ARA on the prostaglandin production in marine fish larvae.  相似文献   

2.
An assay method based on thin layer chromatography to study the arachidonic acid (AA) metabolism in gill tissues was optimized and the effect of osmotically different incubation mediums on AA metabolism was evaluated. Rainbow trout gill tissues metabolize AA into PGE2 in highest concentration followed by PGD2, PGF2 and 6-keto-PGF1 (the stable metabolite of PGI2) among the prostanoids tested. Approximately 40% of PGE2 is synthesized within the first minute of incubation and is directly dependent on the substrate concentration (AA). As in mammalian tissues, PGE2 synthesis in fish gills is inhibited by the cyclooxygenase inhibitor indomethacin. PGE2 synthesis in gill homogenate and isolated gill cells incubated in trout Ringer was 0.45 and 1.9 ng/mg protein, respectively, and increased to 8.9 and 4.3 ng/mg protein, respectively, when incubated in KPO4 buffer, due to a ten-fold increase in the free AA. The hydroxy acid synthesis of the gill homogenate was higher (13%), and that of the isolated gill cells incubated in KPO4 buffer was lower (44%) compared to gill homogenate and cells incubated in trout Ringer. Gill homogenate incubated in 50 mM phosphate buffer with increasing sodium or potassium concentrations (up to 250 mM) exhibited a concentration-dependent increase in PGE2 synthesis (220% and 72%, respectively). Prolactin stimulated the PGE2 synthesis up to 30% while PGD2, PGF2 and 6-keto-PGF1 synthesis was not affected. This effect of prolactin was maximal when PGE2 synthesis was estimated 30 minutes after prolactin addition and diminished after two hours. These results suggest that rainbow trout gills possess the ability to metabolize AA through the cyclooxygenase and lipoxygenase pathways. PGE2 synthesis may be under the influence of ion balance and prolactin availability, indicating the probable involvement of AA metabolites in the regulation of ion balances across the gill membrane.  相似文献   

3.
Ovarian, testicular and seminal vesicle extracts of mature Chinese black sleeper (Bostrichthys sinensis Lacepede), synthetic steroids 17α‐progesterone (17α‐P), 17α,20β‐dihydroxy‐4‐pregnen‐3one (17α,20β‐P) and prostaglandins PGE2 and PGF2α were used in an attempt to attract broodfish and to induce spawning. Furthermore, 17α‐P, PGE2 and PGF2α levels were determined in extracts, and PGE2 and PGF2α levels were determined in holding and spawning waters. The results showed that ovarian extracts attracted more males than females to enter artificial nests, while testicular and seminal vesicle extracts attracted more females than males. The highest percentage of spawned nests were found when 17α,20β‐P and PGE2 were administered to the nests, while the largest egg numbers and the mean highest fertilization rate were observed when PGE2 was added. In ovarian extract, 17α‐P level was higher than levels in testicular or seminal vesicle extracts. The PGE2 levels were significantly (P<0.05) higher than PGF2α in the ovarian, testicular and seminal vesicle extracts. The PGE2 and PGF2α levels in spawning waters were higher than those in holding waters. The PGE2 levels were greatly significantly (P<0.01) higher than PGF2α in spawning and in holding waters. The results suggest that the sex organs of B. sinensis contain 17α‐P, 17α, 20β‐P, PGE2 and PGF2α and that 17α‐P, 17α,20β‐P and PGE2 may act as sex pheromones in this species, attracting both male and female conspesifics to spawning sites and inducing spawning. Among the compounds tested, PGE2 was the most effective sex pheromone for induction of spawning in B. sinensis.  相似文献   

4.
Gonadal steroid and prostaglandin F2α (PGF2α) plasma levels were evaluated in successfully (SP) and unsuccessfully ovulated (UN) female Piaractus mesopotamicus. Forty-one females were injected with crude carp pituitary extract (0.6 and 5.4 mg kg?1 with a 24-h interval between the doses) and sampled to determine the plasma concentration of 17β-estradiol (E2), 17α-hydroxyprogesterone (17α-OHP), 17α,20β-dihydroxy-4-pregnen-3-one (DHP), PGF2α, and testosterone (T) after each injection (first—A1 and second—A2), and at the time of ovulation for SP and UN. Two clusters were obtained using multivariate analysis: 1—composed of all A1, all A2, and some UN; and 2—composed of all SP and some UN. Median values of E2 plasma levels were similar between clusters; however, plasma levels of T, 17α-OHP, DHP, and PGF2α of cluster 2 (predominantly formed by SP) were higher than those of cluster 1. Since cluster 2 contained all SP and females of this cluster presented higher levels of PGF2α, T, 17α-OHP, and DHP, here we evidently shown in an unprecedented manner that concomitant increased levels of these substances were associated with successful ovulation in this species, but such an increase was not determinant for successful ovulation due to the presence of some UN females in the same cluster 2. These findings highlight the unexplored potential of PGF2α to be used as an accessory tool for inducing successful ovulation for fish farming purposes.  相似文献   

5.
A feeding trial was conducted to determine the optimum level and effect of incremental dietary levels of docosahexaenoic acid (DHA, 22:6n‐3) on growth and non‐specific immune responses in juvenile rock bream, Oplegnathus fasciatus. A basal diet without DHA supplementation was used as a control, and six other diets were prepared by supplementing with 4, 8, 12, 16, 20 or 40 g kg?1 DHA. These diets included no eicosapentaenoic acid and/or arachidonic acid contents. The actual DHA concentrations of the diets were 1, 4.8, 8.9, 13.1, 17.6, 21.2 and 41.4 g kg?1 diet (DHA1.0, DHA4.8, DHA8.9, DHA13.1, DHA17.6, DHA21.2 and DHA41.4 respectively). At the end of feeding trial, final body weight, weight gain, specific growth rate and feed efficiency of fish fed the DHA13.1, DHA17.6, DHA21.2 and DHA41.4 diets were significantly higher than those fed the other diets (P < 0.05). The broken‐line analysis of weight gain indicates that the optimum dietary DHA level is 11.9 g kg?1. Fish fed DHA1.0 had the highest hepatosomatic index, an increase in plasma cholesterol, triglyceride, low‐density lipoprotein and aspartate aminotransferase levels, as well as a decrease in high‐density lipoprotein. Superoxide dismutase activity of fish fed DHA13.1 and DHA17.6 diets was significantly higher than that of fish fed DHA1.0, DHA4.8 and DHA8.9 diets. Fish fed the DHA17.6, DHA21.2 and DHA41.4 diets showed significantly higher lysozyme activity than those fish fed DHA1.0, DHA4.8 and DHA8.9 diets. Therefore, the optimum dietary DHA level could be greater than 11.9 g kg?1 but less than 13.1 g kg?1 in diet.  相似文献   

6.
Our previous studies suggested that prostaglandin E2 (PGE2) is a putative sex pheromone in Chinese black sleeper Bostrichthys sinensis, a fish species that inhabits intertidal zones and mates and spawns inside a muddy burrow. We found immunoreactivities of PGE2 receptor subtypes (Ep1–3) expressed in the olfactory sac, but only Ep1 presented higher density of immunoreactivity in mature fish than that in immature fish in both sexes. To gain a better understanding of the underlying molecular mechanism for the detection of PGE2 in the olfactory system, we cloned an ep 1 cDNA from the adult olfactory sac. The open-reading frame of the ep 1 consisted of 1,134-bp nucleotides that encoded a 378-amino acid-long protein with a seven-transmembrane domain, typical for the G protein-coupled receptors superfamily. Expression of ep 1 mRNA was observed in all tissues examined, with higher levels obtained in the olfactory sacs and testes. The expression of ep 1 mRNA in the olfactory sacs and gonads was significantly higher in both sexes of mature fish than in those of immature ones. Taken together, our results suggested that Ep1, which is highly expressed in the olfactory sacs and gonads of mature fish, is important for the control of reproduction and may be involved in PGE2-initiated spawning behavior in B. sinensis.  相似文献   

7.
Five purified diets containing AA (20:4n-6) at 0.02–0.78% dry weight and DHA (22:6n-3) at 0.93–0.17% dry weight were fed to duplicate groups of juvenile turbot (Scophthalmus maximus) of initial weight 0.87 g for a period of 11 weeks. The dietary DHA:AA ratio ranged from 62 to 0.2. Incorporation of AA into liver phospholipids increased with increasing dietary AA input. Phospholipids from fish fed diets containing 0.02, 0.06 and 0.11% of dry weight as AA generally contained less AA compared to fish fed fish oil while those fed diets containing 0.35 and 0.78% of dry weight as AA had higher AA levels in their phospholipids. The highest levels of AA were found in PI but the greatest percentage increase in AA incorporation was in PE and PC. Brain phospholipid fatty acid compositions were less altered by dietary treatment than those of liver but DHA content of PC and PE in brain was substantially lower in fish fed 0.93% pure DHA compared to those fed fish oil. This suggests that dietary DHA must exceed 1% of dry weight to satisfy the requirements of the developing neural system in juvenile turbot. In both tissues, (20:5n-3) concentration was inversely related to both dietary and tissue PI AA concentration. Similar dietary induced changes in AA, EPA and DHA concentrations occurred in the phospholipids of heart, gill and kidney. PGE2 and 6-ketoPGF1 were measured in homogenates of heart, brain, gill and kidney. In general, fish fed the lowest dietary AA levels had reduced levels of prostaglandins in their tissue homogenates while those fed the highest level of AA had increased prostaglandin levels, compared to fish fed fish oil. In brains, the PGE2 concentration was only significantly increased in fish fed the highest dietary AA.Abbreviations AA arachidonic acid - DHA docosahexaenoic acid - EFA essential fatty acid - EPA eicosapentaenoic acid - HPTLC high performance thin-layer chromatography - HUFA highly unsaturated fatty acid - PC phosphatidylcholine - PE phosphatidylethanolamine - PGE prostaglandin E - PGE prostaglandin E - PI phosphatidylinositol - PS phosphatidylserine - PUFA polyunsaturated fatty acid - TLC thin-layer chromatography  相似文献   

8.
Arachidonic acid (AA; 20:4n-6) is the precursor of a range of highly biologically active derivatives, collectively termed eicosanoids, including prostaglandins, thromboxanes, leukotrienes and lipoxins, that act as autocrine hormones regulating many physiological processes including haemostasis, reproduction, immune and inflammatory responses. Eicosapentaenoic (EPA; 20:5n-3) and dihomo-γ-linolenic (20:3n-6) acids modulate eicosanoid metabolism by both inhibiting the conversion of AA to eicosanoids whilst simultaneously being converted to eicosanoids with different, often attenuated, properties compared to their AA homologues. Eicosatetraenoic acid (20:4n-3) is a naturally occurring C20 polyunsaturated fatty acid (PUFA), present in fish oil at levels of around 1–2%, that has been suggested to be the active metabolite responsible for the anti-inflammatory effects of plant oils containing stearidonic acid (18:4n-3). However, the biochemical properties of 20:4n-3 in terms of cellular biology have rarely been investigated, partly due to difficulties in obtaining the fatty acid in high purity. In this paper, we describe methods for the medium scale laboratory preparation of high purity 20:4n-3, and investigate its metabolism in fish cell culture systems which normally contain significant amounts of n-3 PUFA. Thus the incorporation and metabolism of 18:4n-3 and 20:4n-3, and their distribution in phospholipid classes was studied in an established cell line from Atlantic salmon (Salmo salar) (AS), and the effects of 20:4n-3 on eicosanoid production studied in freshly isolated macrophages from rainbow trout (Oncorhynchus mykiss). Both 18:4n-3 and 20:4n-3 were preferentially esterified into phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine in contrast with the accumulation of AA in phosphatidylinositol. Incorporated 18:4n-3 was readily converted to 20:4n-3, and both fatty acids were further desaturated and elongated to EPA and 22:5n-3 but not 22:6n-3. Supplementation with 20:4n-3 decreased the conversion of AA into prostaglandins, as demonstrated by the decreased levels of PGF2α produced in trout macrophages supplemented with 20:4n-3 and AA compared to cells supplemented with AA alone. In addition, 20:4n-3 was converted into eicosanoids in fish cells as indicated by the presence of Δ17,18 12-HETE, Δ17,18 PGE1 and Δ17,18 PGF1α in extracts from rainbow trout macrophages incubated with 20:4n-3.  相似文献   

9.
Staining-type hypermelanosis, defined as blind-side melanosis occurring after completion of metamorphosis, reduces commercial value in hatchery-produced flatfishes. Detailed characterization was performed on the stained area of juvenile Japanese flounder Paralichthys olivaceus to physiologically understand this phenomenon. From 80 to 120 days after hatching, juveniles were reared in sandy and sandless tanks. By classifying the staining degree into 7 levels, about 2 times higher occurrence of middle-level staining was reconfirmed in sandless tank (about 80 %) than in sandy tank (about 40 %). In the stained area, we found 3 types of chromatophores (melanophore, xanthophore, and iridophore) and ctenoid scales, which would be typically observed on the normal ocular side. Detailed examination on the melanophores revealed further similarity between the stained area and the normal ocular side, in terms of the distribution at 2 layers (shallower and deeper than scale), and the densities in both layers (about 1000 cells/mm2 above scale and 200 cells/mm2 beneath scale). These results strongly suggest that the staining is a status change in the body surface conditions from the blind side to that on the ocular side, and not a simple darkening caused by disordered proliferation of melanophores on the blind side.  相似文献   

10.
Red carp and red crucian carp are ornamental fish with a red body color. Unlike in red crucian carp, no melanophores are observed in red carp embryos or larvae. To explore the roles of the mitfa gene in body color formation in red carp, we investigated the structural characteristics and physicochemical properties of the mitfa gene in 16 kinds of fish. The mitfa amino acid sequence similarity between red carp and red crucian carp was 95.6%, and this was 91.5% similar between carp and zebrafish. Compared with red crucian carp, red carp showed lower tyrp1 messenger ribonucleic acid (mRNA) expression but similar mitfa mRNA expression in the body pigment stage of the embryo. Moreover, mitfa+ cells as well as melanocytes could be observed in cultured embryo cells derived from red carp and red crucian carp. Our data show that the absence of melanophores in red carp is not the result of mitfa gene deletion or mutation, increasing our understanding of the molecular and genetic mechanisms of coloration in cyprinid fish.  相似文献   

11.
Prostaglandins are involved in the reproductive processes in a variety of animals, including crustaceans. It was found that polychaetes, the best maturation diet for shrimp broodstock, possessed the greatest variation of prostaglandin E2 (PGE2) when compared with other live feeds. The level of PGE2 varied according to sizes, feed intake, sources and type of polychaete. The matured and also larger sand polychaete Perinereis sp. contained higher PGE2 levels than younger and smaller sand polychaetes (18.16 ± 5.82 ng PGE2 mg−1 protein for polychaetes at an average length of 10 cm up to 160.8 ± 37.09 ng PGE2 mg−1 protein for polychaetes at an average length of 17 cm). The PGE2 levels in ovaries and haemolymph of female shrimp fluctuated with the developmental stage of the ovaries. The highest concentration of PGE2 in haemolymph was at stage 3 of ovarian development, whereas the highest concentration of PGE2 in shrimp ovaries was at stage 4. In vitro incubation of Penaeus monodon pre-vitellogenic oocytes with polychaete extract and synthetic PGE2 demonstrated that both PGE2s enhanced oocyte development, especially during late development and ovulation. The putative role of PGE2 from polychaetes or the presence of PGE2 in polychaetes may be a factor in their role as a dietary constituent required for shrimp oocyte development.  相似文献   

12.
The pharmacokinetics of oxolinic acid (OA) were investigated after a single intra‐vascular injection (20 mg kg?1 fish) in sharpsnout sea bream (90 g), a promising new euryhaline species for Mediterranean fish farming. The distribution half‐life (t1/2α) and the elimination half‐life (t1/2β) of OA were calculated to be 0.4 and 10 h respectively. The apparent volume of distribution at steady‐state (Vd(ss)) and total clearance rate (CLT) of the drug were found to be 2.1 L kg and 0.2 L kg?1 h?1 respectively. The bioavailability (F%) of OA following oral administration (40 mg kg?1 fish) was estimated to be 15%. The results indicate a rapid distribution and elimination of the drug, moderate tissue penetration, but low absorption in sharpsnout sea bream. The kinetic profile of OA found in this species is comparable with that observed in another well‐known sparid, gilthead sea bream.  相似文献   

13.
This study was conducted to investigate the effects of dietary propolis supplementation on growth performance, immune responses, disease resistance and body composition of juvenile eel, Anguilla japonica, in order to evaluate its bioavailability as a feed additive for this species. A total of 540 fish averaging 7.7?±?0.22?g (mean?±?SD) were randomly distributed into 18 tanks in groups of 30, and each tank was then randomly assigned to one of three replicates of six diets containing 0 (P0), 0.25 (P0.25), 0.5 (P0.5), 1.0 (P1), 2.0 (P2) and 4.0 (P4) % dietary propolis. At the end of 12?weeks of feeding trial, weight gain (WG), specific growth rate (SGR), feed efficiency (FE) and protein efficiency ratio (PER) of fish fed P0.5 diet were significantly higher than those of fish fed P0, P1, P2 and P4 diets (P?<?0.05). These parameters were 148.9%, 0.72% day?1, 94.4% and 2.9, respectively for fish fed P0.5 diet. Serum lysozyme activity of fish fed P0.5 (105.7 units mL?1) and P1 (106.0 units mL?1) diets were significantly higher than those of fish fed P0, P0.25, P2 and P4 diets. Mucus lysozyme activity of fish fed P1 (8.4 units 10?cm?2) diet was significantly higher than those of fish fed P0, P2 and P4 diets. Results indicated that the optimum dietary propolis supplementation levels could be 0.25?C0.5% for optimum growth and feed efficiency, and 0.5?C1% for enhanced immune responses and disease resistance in eel, A. japonica. This study may suggest that the dietary propolis level for the optimum immune responses could be higher than the level for the optimum growth of eel.  相似文献   

14.
Vegetable oils, typically high in n − 6 fatty acids, are necessary alternatives in fish feed production. Such oils have been tested in salmonid diets with good growth results, but with major changes in lipid composition. The aim of this study was to provide information regarding the effect of the higher dietary n − 6/n − 3 fatty acid ratio caused by vegetable oil on growth, chemical composition and bone development, on eicosanoid production and on formation and mineralization of bone.A feeding experiment was carried out in juvenile Atlantic salmon (Salmo salar). Groups of fish (1.28 g) were fed diets added fish oil (FO) or soybean oil (SO) as the main lipid source through the 174 days long experimental period with sampling points at days 0, 31, 53, 96, 136 and 174 up to smoltification. Subsequently, fish performance was observed after 2, 8 and 18 months in sea water.Weight was significantly higher in the fish oil group (95.4 g) than in the soybean oil group (87.4 g) after the 174 days experimental period. This difference developed during short day treatment prior to smoltification, and the fish oil group had a significantly higher growth rate (TGC) during this period (1.62 vs 1.45). Whole body mineral analysis displayed low levels of Ca (2400 and 3500 mg kg−1) and P (3200 and 3900 mg kg−1) in all samples. The corresponding Ca:P ratio ranged from 0.74 to 0.91. On day 136 the level of Ca, and Ca/P ratio, were significantly higher in the fish oil group than in the soybean oil group. There was a significant increase in n − 6 fatty acids and decrease in n − 3 fatty acids in the soybean oil group compared to the fish oil group for both TAG and PL in vertebrae. Individual variation was large in plasma prostaglandin E2 (PGE2), and at day 174 the trend was towards a higher level in the soybean oil group. Radiography analyses demonstrated a distinctive pattern of development of spinal pathology with time and fish size, similar in both groups. Hyper dense vertebrae dominated at earlier stages, fusion-type malformations dominated at harvest size. The histological examination of the vertebrae revealed no differences between treatments.The results suggest that vegetable oil as a replacement for fish oil influence the arachidonic acid level in phospholipids of vertebrae, may slightly increase production of PGE2 in blood, and reduce vertebrae mineralization around the sensitive smoltification phase. These trends did not lead to any detectable skeletal malformations. Differences in growth and vertebrae mineralization observed around smoltification disappeared during the seawater phase.  相似文献   

15.
The development of Atlantic salmon (Salmo salar) parr was monitored during the first year in a fresh-water hatchery environment to test whether multilocus heterozygosity (computed for six allozyme loci: s AAT-4*, IDDH-1*, IDDH-2*, IDPH-3*, s MDH-3,4* andm MEP-2*) is associated with growth (body mass, fork length) and maturity status (mature male parr). The length frequency distribution of population was unimodal in September, but was clearly bimodal by December. UMG fish tended to be more heterozygous and had higher growth rates than LMG fish. The heterozygosity of UMG fish and mature male parr (MMP) did not differ significantly but MMP showed lower growth rates than UMG. There were positive correlations between the number of heterozygotic loci and the fork length, weight or growth rates of individuals.  相似文献   

16.
Relationships between dietary lipid source, stress, and oxidative stress were examined in juvenile chinook salmon (Oncorhynchus tshawytscha). Four different experimental diets were used: menhaden oil (MHO; elevated 20:5n-3 and 22:6n-3), soybean oil (SBO; elevated 18:2n-6), linseed oil (LSO; elevated 18:3n-3), and a mixture of 55% linseed oil and 45% soybean oil (MIX; approximately equal levels of 18:2n-6 and 18:3n-3). Juvenile salmon (initial body weight of 16.0 g) were fed experimental diets for 12 weeks (early March to early June). At the end of feeding, fish subjected to a low-water stressor for 96 h had greater liver and brain lipid peroxidation compared to unstressed controls; peroxidation was not influenced by diet. Diet and stress affected plasma cortisol levels. Stressed fish fed SBO had the greatest cortisol concentrations, followed by MIX, MHO, and LSO (mean concentrations for the SBO and LSO diets differed significantly). The cortisol response to stress may have been influenced by the ratio of prostaglandin 1- and 2-series to prostaglandin 3-series precursor fatty acids provided by the different diets. The results of this study suggest a connection between the physiological response to stress, dietary lipid quality, and oxidative stress. This is the first evidence of such a relationship in fish. Abbreviations: AA - arachidonic acid; ACTH - adrenocorticotropin; BHT - butylated hydroxytoluene; BLPO - brain lipid peroxidation; dGLA - dihomo-γ-linolenic acid; DHA - docosahexanoic acid; EPA - eicosapentanoic acid; FER - feed efficiency ratio; FOX - ferrous oxidation-xylenol orange; GLA -γ-linolenic acid; LA - linoleic acid; LCO3 - long-chain n-3 polyunsaturated fatty acids; LLPO - liver lipid peroxidation; LN - linolenic acid; LPO - lipid peroxidation; LSO - linseed oil; MHO - menhaden oil; MIX - 55% linseed oil + 45% soybean oil; PC - plasma cortisol; PG - prostaglandin(s); PGE2- prostaglandin E2; PUFA - polyunsaturated fatty acid; SBO - soybean oil. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

17.
Chloramphenicol (CAP) is a banned substance in fish farming; yet, residues are sometimes detected in farmed fish products. Therefore, it is important that tissue distribution and elimination rates of CAP are measured to allow monitoring of fish farms. The tissue distribution and residue of CAP in carp (Cyprinus carpio L.) after muscle injection was investigated. Chloramphenicol concentrations were determined using high‐performance liquid chromatography. Pharmacokinetics were used for the studies of CAP residue and the results showed that the CAP was easily assimilated in the liver, serum and gill, with the absorption rates of 6383, 3.02 and 1.39 h?1, respectively, following a single‐dose injection of 80 mg kg bw?1. The elimination half‐lives (t1/2) were 22.28, 15.47, 14.87, 9.28 and 5.32 h for the liver, serum, gill, muscle and kidney respectively. The t1/2 after 5 days of multi‐doses of repeated CAP injection with 40 mg kg bw?1 was 1.09, 0.887, 0.872, 0.476 and 0.617 days for the five tissues respectively. The results validated that CAP in the liver, serum and gill could be markers for CAP residue analysis.  相似文献   

18.
The incorporation, and the capacity for desaturation and elongation in vivo, of intraperitoneally-injected,14C-labelled n-3 and n-6 C18 and C20 polyunsaturated fatty acids (PUFA) were investigated in juvenile golden grey mullet,Liza aurata. The results indicate that juvenile mullet have only limited ability to convert C18 polyunsaturated fatty acids to C20 and C22 highly unsaturated fatty acids (HUFA)in vivo. This suggests that juvenile golden grey mullet require the provision of preformed C20/22 HUFA, such as eicosapentaenoic and docosahexaenoic acids, in the diet. The impairment in the desaturase/elongase pathway was similar to that found in turbot,Scophthalmus maximus, and gilthead sea bream,Sparus aurata, being primarily at the level of Δ5-desaturase. The data from the largely herbivorous golden grey mullet juveniles are consistent with the hypothesis that marine fish in general, irrespective of dietary habits, have limited capacity for the desaturation and elongation of C18 PUFA. The defect in Δ5-desaturase activity combined with the consistent finding that arachidonic acid is selectively incorporated and retained in membrane phosphatidylinositol suggests that, like turbot and gilthead sea bream, golden grey mullet may also have a requirement for preformed arachidonic acid in the diet.  相似文献   

19.
An inactivated betanodavirus, red‐spotted grouper nervous necrosis virus (RGNNV), is a vaccine candidate for viral nervous necrosis (VNN). The present study was conducted to examine inoculation doses of the vaccine and neutralizing antibody titre levels to protect fish against VNN. Young sevenband grouper, Epinephelus septemfasciatus, averaging 25.4 g, were immunized at 25 °C water temperature by a single intraperitoneal injection of formalin‐inactivated RGNNV. Fish immunized at vaccine doses of 108.5, 108.0, 107.5, 107.0 and 106.5 TCID50 per fish produced antibodies at mean titres of 1:907, 1:511, 1:259, 1:197 and 1:96, respectively, at 20 days post‐immunization (p.i.). Neutralizing antibodies were not detected in any control fish (titre <1:80). When fish were challenged with RGNNV (105.0 and 104.0 TCID50/fish) at 20 days p.i., cumulative mortalities of the fish groups immunized with 108.5, 108.0, 107.5 and 107.0 TCID50 per fish were significantly lower than those of the control group, and the relative percent survival values were higher than 60% in fish groups immunized with 107.5 TCID50 per fish or higher doses. However, no significant differences were found in mortality between the group immunized with 106.5 TCID50 per fish and the control group. From these results, it was deduced that the minimum effective inoculation dose of the vaccine is 107.0 TCID50 per fish and the minimum mean neutralizing antibody titre giving significant protection is approximately 1:200. This antibody titre level is a possible measure of vaccine efficacy against VNN in sevenband grouper, instead of a virus challenge test.  相似文献   

20.
Ammonia is the most common contaminants found in aquaculture water that seriously endangers fish health. However, there are few studies on the strategy and mechanism on alleviating ammonia toxicity in fish. The current study aimed to observe the cytotoxic effects of ammonia and the protective effects of chlorogenic acid (CGA) on head kidney macrophage of yellow catfish from the perspective of inflammation, oxidative stress and apoptosis. The cells were randomized into normal control, ammonia group (0.23 mg L?1), CGA group (125 µmol L?1), CGA (5, 25, 125 µmol L?1) + ammonia (0.23 mg L?1) groups. Cells were pretreated with CGA for 1 h followed by ammonia for 24 h. Findings suggested that ammonia treatment reduced cell viability, increased ROS production, up-regulated antioxidant (SOD, GPx) and pro-inflammatory (TNF-α, IL-1, IL-6, COX-2, NF-κB p65) genes expression, down-regulated the mRNA levels of M2-type macrophage marker (Arg-1) and anti-apoptosis (Bcl-2), and CGA attenuated the toxic effects of ammonia. The findings may provide insight into the underlying mechanisms of ammonia toxicity and suggest that CGA can be used as a potential natural supplement to alleviate ammonia toxicity in fish.  相似文献   

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