Effects of varying levels of dietary vitamin E (α‐tocopherol) on growth performance,proximate and fatty acid composition of juvenile silver pomfret (Pampus argenteus Euphrasen, 1788)

This study investigated the effects of elevated dietary levels of vitamin E (α‐tocopherol) on growth performance, proximate composition and fatty acid profiles of juvenile silver pomfret, Pampus argenteus. Three semi‐purified experimental diets were formulated to contain 49% protein and 16% lipid. High docosahexaenoic acid (DHA) tuna oil was added to the diets to supplement DHA. A graded level of vitamin E (0‐, 50‐, and 100 mg kg^?1) was added to experimental diets 1 to 3, respectively. Analyzed vit. E levels were 155.2, 195.3 and 236.4 mg kg^?1 in diets 1, 2 and 3, respectively. The experiment was conducted for 12 weeks with juvenile silver pomfret (29.6 ± 7.6 g) using a flow‐through system consisting of nine 1‐m³ tanks. Each treatment had three replicates and fish were stocked at the rate of 20 m^?3. Growth performance and feed utilization parameters of fish fed diets 2 and 3 were significantly (P < 0.05) higher than in fish fed diet 1, but the parameters in diets 2 and 3 did not differ significantly (P > 0.05). Although whole body protein levels were not influenced by the dietary vit. E levels, whole body lipid in fish fed diet 2 was significantly higher than in fish fed the other diets. The whole body vit. E levels in fish fed diet 2 (22.6 mg kg^?1) and diet 3 (24.1 mg kg^?1) were significantly (P < 0.05) higher than in those fed diet 1 (18.2 mg kg^?1). Whole body total saturated fatty acids were significantly lower, and DHA levels higher in fish fed diets 2 and 3 than those fed diet 1. The results of the present study suggest that increasing dietary supplementation of vit. E in high lipid diets enhances the growth performance of fish and that a dietary level of 196 mg kg^?1 vit. E is suitable for the growth of silver pomfret.     

Evaluation of optimum dietary vitamin E requirements using DL‐α‐tocopheryl acetate in the juvenile eel,Anguilla japonica

The study aimed at evaluating the optimum dietary vitamin E requirements using DL‐α‐tocopheryl acetate in the juvenile eel, Anguilla japonica, as assessed by fish growth performance and fish body composition. Five semi‐purified experimental diets were formulated to contain 0 (TA₁), 15 (TA₁₇), 30 (TA₃₂), 60 (TA₆₂) and 120 (TA₁₁₉ mg TA kg^?1 diet on a dry matter (DM) basis in the form of DL‐α‐tocopheryl acetate (TA). After a 4‐week conditioning period, fish (15 ± 0.3 g) were randomly distributed into aquaria in groups of 20 at 25 ± 1.0°C (mean ± SD). One of the five diets was fed on a DM basis to fish in three randomly selected aquaria twice daily to satiation (approximately 3% of wet body weight per day at the beginning and 2% of wet body weight per day at the end of the feeding trial) for 12 weeks. At the end of the 12‐week feeding trial, weight gain (WG), specific growth rate (SGR), feed efficiency (FE) and protein efficiency ratio (PER) were determined; these were significantly lower in control fish than in fish fed supplemented diets (P < 0.05). The values for fish fed TA₁₇ were significantly higher than for fish fed TA₁, TA₆₂ or TA₁₁₉ (P < 0.05). There were no significant differences in WG, FE or PER among fish that were fed TA₁₇ and TA₃₂, among those that were fed TA₃₂ and TA₆₂, and among those that were fed TA₆₂ and TA₁₁₉ (P > 0.05). There were also no significant differences in SGR among fish fed TA₃₂, TA₆₂ or TA₁₁₉ (P > 0.05). A broken‐line regression analysis on the basis of WG, SGR, FE and PER showed that dietary vitamin E requirements of juvenile eels were 21.2, 21.6, 21.2 and 21.5 (mg kg^?1 diet), respectively. These results indicate that the dietary vitamin E requirement could be <21.2 mg kg^?1 but <21.6 mg kg^?1 diet in juvenile eel, A. japonica, when DL‐α‐tocopheryl acetate is used as the dietary vitamin E source.     

Effects of norfloxacin on the drug metabolism enzymes of two sturgeon species (Acipenser schrencki and Acipenser ruthenus)

The enzyme activities of 7‐ethoxycoumarin O‐deethylase (ECOD) and glutathione S‐transferase (GST), and on glutathione (GSH) content, involved in metabolism of the antibiotic Norfloxacin (NFLX), were investigated in Acipenser schrencki and Acipenser ruthenus. Sturgeons weighing 45–55 g were kept in an aquarium (0.5 m × 0.5 m × 0.9 m) for two weeks under controlled conditions (fish density 88 individuals per m³, 18°C) before the experiment. The two species of sturgeon were divided into five groups each (n = 15 in each group), with each group subdivided into three replicates of five fish per tank. A control group in which distilled water was administered orally was also tested. NFLX was forced into the stomachs of the fish at a concentration of 20, 40, 60, 80 and 100 mg kg^?1 body weight, respectively. ECOD activities in liver microsomes, and GST activity and GSH content in liver microsomes and blood plasma, were measured and compared. Results indicate that ECOD activity is progressively inhibited with increasing NFLX concentrations. ECOD activity varied from 0.12 nmol mg^?1 min^?1 to 0.07 nmol mg^?1 min^?1, demonstrating an inhibition rate of 60.83% in A. schrencki and 65.14% in A. ruthenus. In both species tested, GST and GSH levels exhibited a trend of first increasing, and then decreasing with increasing NFLX levels, reaching a peak value at 40 mg per kg^?1 body weight. Thus, the presented results indicate that NFLX can induce a change in the activity of some drug metabolism related enzymes such as ECOD and GST in vivo.     

Liver alteration and hematological and serum biochemical responses of common carp,Cyprinus carpio Linnaeus, 1758, following long‐term feeding of pistachio (Pistacia vera) green hull extract as a source of natural phenol

This study was conducted to investigate the effect of pistachio green hull extract (PGHE) on hematological and serum biochemical changes in common carp, Cyprinus carpio. Three hundred common carp (11.65 ± 1.65 g) were fed one of five different dietary treatments (with three replications) containing 0, 0.5, 1.5, 4.5 or 9 g PGHE kg^?1diet for ten continuous weeks. Each tank had a 90‐L capacity and water flow rate of about 500 ml min^_1.Total phenolic compounds of the different diets differed significantly (P < 0.001) according to the amount of PGHE. At the end of experiment, six fish were removed randomly from each treatment. Blood samples were taken for hematological and serum biochemical analyses at room temperature. Liver tissue samples were processed for histology and stained by H&E. The results indicated that all doses of tested PGHE induced no significant changes in hematocrit, hemoglobin, or erythrocytes, nor alkaline phosphatase, alanine transaminase, lactate dehydrogenase, total protein, albumin, globulin, triglycerides, low‐density lipoprotein, high‐density lipoprotein, glucose or cholesterol in the serum. Leukocytes were higher (P < 0.01) in fish fed a 1.5, 4.5, or 9 g PGHE kg^?1 diet when compared to the 0.5 g PGHE kg^?1 diet group or the control. Serum aspartate transaminase in treatments containing a 4.5 or 9 g PGHE kg^?1 diet was significantly (P < 0.001) higher in comparison with the control. Liver histology showed focal necrosis, cytoplasm degeneration, lateral nuclei and an increase in Kupffer cells following PGHE administrations. The results of this trial indicated that although there were no significant changes in most hematological and biochemical parameters, PGHE could induce some adverse pathological effects on liver tissue.     

Effects of β‐xylanase and 6‐phytase on digestibility,trace mineral utilisation and growth in juvenile red tilapia,Oreochromis niloticus (Linnaeus, 1758) x O. mossambicus (Peters, 1852), fed declining fishmeal diets

In response to the global sustainability drive to lower fishmeal (FM) inclusion in aquatic feeds, exogenous enzymes can improve nutrient digestibility in monogastric plant‐based diets. A 80‐day experiment was conducted to evaluate the combined effects of xylanase and phytase on digestibility, trace mineral utilisation and growth in juvenile red tilapia, Oreochromis niloticus x O. mossambicus, (48.8 g ± 13.9; μ ± STD) fed declining FM diets. Basal diets were formulated to contain 0, 3 and 5% FM with and without xylanase (0.385 g kg^?1) and phytase (0.075 g kg^?1), forming six treatments. Each treatment was randomly assigned to four replicates, 20 fish tank^?1; mean water temperature 28.98 ± 0.73°C. Although the size of the effects was modest, growth performances (feed intake, FCR, growth rate) decreased with lower FM levels (P < 0.05) but improved with enzyme supplementation. Enzyme supplementation increased P digestibility and trace mineral uptake (P < 0.05), but no effects were seen on protein digestibility and N retention. Nevertheless, tilapia fed the enzyme‐supplemented 3% FM and control 5% FM diets performed comparably (P < 0.05). This potentially justifies a 2% FM reduction for tilapia diets using exogenous xylanase and phytase without significant effects on digestibility, trace mineral utilisation and growth.     

Effect of dietary dextrin levels on the growth performance,blood chemistry,body composition,hepatic triglicerides and glycogen of Lebranche mullet juveniles (Mugil liza Valenciennes 1836, Mugilidae)

The effects of increasing levels of dietary dextrin on growth performance, body composition, blood chemistry and hepatic triglycerides and glycogen levels were evaluated for juvenile Lebranche mullet, Mugil liza Valenciennes 1836, Mugilidae). Five diets were formulated to be isonitrogenous (350 g kg^?1) and isolipidic (6 g kg^?1) with increasing dextrin levels (D150: 150 g kg^?1; D200: 200 g kg^?1; D250: 250 g kg^?1; D300: 300 g kg^?1; D350: 350 g kg^?1). The experimental diets were offered to the fish for 34 days, four times per day, until apparent satiation. Each treatment was tested in triplicate, with nine fish per tank (mean weight 4.69 ± 0.31 g). Fish were reared in a recirculating aquatic system of 15 fibreglass tanks each containing 50 L of saltwater. Growth parameters and body composition of the mullets were not significantly affected (P > 0.05) by the dietary treatments. Plasma glucose concentration declined (P < 0.05) when dietary dextrin increased from D250 to D300, but recovered to the previous values (in reference to D150 and D200) when fish were fed with D350. Glycated haemoglobin, plasma proteins, triglycerides and cholesterol showed no significant differences among these treatments. Hepatic glycogen reached a maximum in treatment D250, followed by D350, D200 and D300, with the lowest concentration of liver glycogen found in D150 (P < 0.05). The concentration of liver triglycerides showed an increase (P < 0.05) in treatments D300 and D350 compared with D200. In conclusion, Mugil liza juveniles can be fed diets with high levels of dietary dextrin with no deleterious effects to their growth or plasma biochemistry, hepatic glycogen or triglycerides.     

Effects of different concentrations of 2‐phenoxyethanol on primary and secondary stress responses in Persian sturgeon,Acipenser persicus

The anaethetic effects of 2‐phenoxyethanol (2‐PE) on possible primary (cortisol level) and secondary (hematological indices and glucose level) stress responses were studied in Persian sturgeon (Acipenser persicus). Fish were first exposed to 0.1, 0.3, 0.5, 0.7, 0.9 and 1.1 ml L^?1 2‐PE, and the time to induction (deep anaethesia) and recovery were measured. At a concentration of 0.1 ml L^?1, 2‐PE failed to induce deep anaethesia in fish, whereas at concentrations of 0.7, 0.9 and 1.1 ml L^?1 all fish were anaethetized within 3 min of exposure. For assessing possible stress effects caused by effective concentrations of 2‐PE, the hematological indices, serum cortisol and glucose were determined in the deeply anaethetized fish as stress indicators. The 2‐PE exposure resulted in significant increases in red blood cell (RBC) values at 0.3 and 0.5 ml L^?1; parallel increases in hemoglobin values were also observed at these concentrations (P < 0.01). Moreover, a lower concentration of 2‐PE (0.3 ml L^?1) caused a significant increase in hematocrit values (P < 0.05). Among the hematological indices, mean corpuscular volume (MCV) values decreased at 0.5 ml L^?1 when compared with the control and other groups (P < 0.05). Serum cortisol level was elevated at 0.3, 0.5 and 0.7 concentrations of 2‐PE (P < 0.01). The glucose level followed a trend similar to that observed for cortisol. The outcome of these experiments shows that 2‐PE at a concentration of 0.9 ml L^?1 is a suitable anaesthetic for Persian sturgeon. This study demonstrates that rapid induction of deep anaethesia with a relatively high concentration of 2‐PE (0.9 and 1.1 ml L^?1) was associated with the lowest effects on signs of physiological stress in Persian sturgeon.     

Effect of prebiotic mannan oligosaccharide on hematological and blood serum biochemical parameters of cultured juvenile great sturgeon (Huso huso Linnaeus, 1754)

The nutritional effects of prebiotic mannan oligosaccharide were evaluated using hematological and blood serum biochemical parameters in cultured juvenile great sturgeon (Huso huso). Fish were offered formulated diets containing two levels of prebiotic mannan oligosaccharide (2 and 4 g kg^?1); a basal diet with no prebiotics was used as control. The experiment lasted for 46 days. Blood samples were collected from the caudal veins of 18 apparently healthy fish (average weight 217.77 ± 29.8 g) at the end of the trial. No significant differences were found in the serum enzyme activity levels between treatments (P > 0.05). However, adding mannan oligosaccharide as a supplement to the basal diet resulted in significant differences in lymphocytes and eosinophils between the control and the 2 g kg^?1 treatment (P < 0.05) as well as a significant difference in the creatinine factor in the 2 g kg^?1 mannan oligosaccharide treatment (P < 0.05). The results show that it would be advantageous to add 2 g kg^?1 mannan oligosaccharide to the diets of juvenile great beluga sturgeon (Huso huso).     

Influence of feeding the leucine metabolite β-hydroxy-β-methylbutyrate (HMB) on the non-specific cellular and humoral defence mechanisms of rainbow trout (Oncorhynchus mykiss)

Previous studies have shown that leucine metabolite β‐hydroxy‐β‐methylbutyrate (HMB) increases the immune function in animals as measured by cellular and humoral immune responses. In the present study the influence of feeding HMB on the nonspecific cellular and humoral defence mechanisms and protection against furunculosis in rainbow trout (Oncorhynchus mykiss) was examined. HMB was fed in a pelleted ration at either 0 (control), 10, 25 or 50 mg  kg^?1 bw day^?1 for 8 weeks. Blood and pronephros cells were taken at random from 10 fish in each group for the analyses. The respiratory burst activity (RBA) and potential killing activity (PKA) of phagocytes, lymphocyte proliferation stimulated by either concanavalin (ConA) or lipopolysaccharide (LPS), lysozyme activities and total immunoglobulin (Ig) levels in plasma were analysed at 0, 1, 2, 3, 4, 6 and 8 weeks. After 4 weeks of feeding HMB, a challenge test was performed by injection of Aeromonas salmonicida into the fish. HMB approximately doubled the respiratory burst activity and potential killing activity ability of polymorphonuclear (PMN) and morphonuclear (MN) cells (P < 0.01) and increased the mitogen‐stimulated lymphocyte proliferation (P < 0.01) when compared with the control group. HMB feeding also increased (P < 0.01) the lysozyme activity in plasma and total Ig levels in serum. During the 14‐day challenge test, mortality was decreased (P < 0.01) by up to 62% in HMB‐fed fish compared with the control group mortality. In conclusion, the non‐specific immune enhancement by HMB resulted in protection against furunculosis in the rainbow trout.     

Growth Performance,Hemato-Immunological Responses,and Digestive Enzyme Activities in Silvery-Black Porgy (<Emphasis Type="Italic">Sparidentex hasta</Emphasis>) Fed Dietary Bovine Lactoferrin

An 8-week study was conducted to evaluate three different diets supplemented with bovine lactoferrin (LF) at 0 (control), 800, and 1200 mg LF kg^?1 diet on somatic growth, hemato-immunological parameters, antioxidant status, and digestive enzyme activities in silvery-black porgy (Sparidentex hasta) juveniles. Fish fed the 800 mg LF kg^?1 diet had higher growth performance and feed utilization parameters than the other groups. Hematological and liver antioxidant parameters were not affected by dietary LF supplementation. Fish fed the 800 mg LF kg^?1 diet had higher plasma lysozyme activity values than the other groups. Total protease activity was higher in fish fed LF-supplemented diets than the control group. Results indicated that diet supplemented with 800 mg kg^?1 for 8 weeks enhanced somatic growth performance, lysozyme activity, and proteolytic digestive enzyme activities in S. hasta, as well as improving feed efficiency parameters like the protein efficiency and feed conversion ratios.     

Vitamin E and Hippophea rhamnoides L. extract reduce nicotine‐induced oxidative stress in rat heart

The effects of vitamin E and Hippophea rhamnoides L. extract (HRe‐1) on nicotine‐induced oxidative stress in rat heart were investigated. There were eight rats per group and supplementation period was 3 weeks. The groups were: nicotine [0.5 mg kg^?1day^?1, intraperitoneal (i.p.)]; nicotine plus vitamin E [75 mg kg^?1day^?1, intragastric (i.g.)]; nicotine plus HRe‐1 (250 mg kg^?1day^?1, i.g.); and the control group (receiving only vehicles). Nicotine increased the malondialdehyde level, which was prevented by both vitamin E and HRe‐1. Glutathione peroxidase (GPx) activity in nicotine plus vitamin E supplemented group was higher than the others. Glutathione S‐transferase (GST) activity in nicotine plus HRe‐1 supplemented group was increased compared with the control group. Catalase activity was higher in nicotine group compared with others. GPx activity in nicotine plus vitamin E supplemented group was elevated compared with the others. Total and non‐enzymatic superoxide scavenger activities in nicotine plus vitamin E supplemented group were lower than nicotine plus HRe‐1 supplemented group. Superoxide dismutase (SOD) activity was higher in nicotine plus HRe‐1 supplemented group compared with others. Glutathione reductase activity and nitric oxide level were not affected. Increased SOD and GST activities might have taken part in the prevention of nicotine‐induced oxidative stress in HRe‐1 supplemented group in rat heart. Flavonols such as quercetin, and isorahmnetin, tocopherols such as α‐tocopherol and β‐tocopherol and carotenoids such as α‐carotene and β‐carotene, reported to be present in H. rhamnoides L. extracts may be responsible for the antioxidant effects of this plant extract. Copyright © 2010 John Wiley & Sons, Ltd.     

Inhibition effects of pesticides on glutathione‐S‐transferase enzyme activity of Van Lake fish liver

Glutathione‐S‐transferases (GSTs) have a function in xenobiotic metabolism. They are a significant multifunctional family with a wide variety of catalytic activities. In the current study, we determined in vitro inhibition effects of 2,4‐dichlorophenoxyacetic acid dimethylamine salt (2,4‐D DMA), haloxyfop‐P‐methyl, glyphosate isopropylamine, dichlorvos, and λ‐cyhalothrin on purified GST. For this purpose, GST were purified from Van Lake fish (Chalcalburnus tarichii Pallas) liver with 29.25 EU mg^?1 specific activity and 10.76% yield using GSH–agarose affinity chromatographic method. The pesticides were tested at various concentrations on in vitro GST activity. K_i constants were calculated as 0.17 ± 0.01, 0.25 ± 0.05, 3.72 ± 0.32, 0.42 ± 0.06, and 0.025 ± 0.004 mM, for 2,4‐D DMA, haloxyfop‐P‐methyl, glyphosate isopropylamine, dichlorvos, and λ‐cyhalothrin, respectively. λ‐Cyhalothrin showed a better inhibitory effect compared to the other pesticides. The inhibition mechanisms of λ‐cyhalothrin were competitive, while the other pesticides were noncompetitive.     

Partial replacement of monocalcium phosphate with neutral phytase in diets for grass carp,Ctenopharyngodon idellus

A 9‐week experiment was designed to study the effects of partial replacement of monocalcium phosphate (MCP) with neutral phytase on growth, body compositions, serum biochemical statuses and intestinal digestive enzyme activities of grass carp, Ctenopharyngodon idellus. The control diet (designated as P2.0) was prepared with 2.0% MCP but without phytase. The three other diets (designated as PP1.5, PP1.0 and PP0.5, respectively) were supplemented with 1.5, 1.0 and 0.5% MCP, respectively, along with 500 FTU of neutral phytase kg^?1 diet in each. After a 9‐week feeding trial, fish (initial body weight: 43.44 ± 2.37 g) fed with PP1.5 and PP1.0 had no significant change in weight gain (WG), specific growth rate (SGR), protein efficiency rate (PER) or feed conversion ratio (FCR) compared with the control (P > 0.05) whereas fish fed with PP0.5 showed significantly lower growth performance in the above parameters. The crude lipid content in whole body or muscle of the fish fed with PP1.5 was significantly lower than the control while significantly higher in fish fed with PP0.5 (P < 0.05), whereas no obvious change was observed in the fish fed with PP1.0. For serum indices, higher serum alkaline phosphatase (Alkp), phosphorus (P) and calcium (Ca) contents were observed in fish fed with phytase‐supplemented diets in comparison with the control. In addition, dietary phytase supplementation increased amylase activity and decreased lipase activity in both foregut and hindgut. The present study suggests that dietary MCP can be reduced when neutral phytase is added to the grass carp diet, and that the maximum MCP reduction level can be up to 1% when neutral phytase is supplemented at 500 FTU kg^?1 diet.     

Ionregulation in juvenile swordspine snook (Centropomus ensiferus,Poey, 1860) in relation to environmental salinity

Ninety‐nine swordspine snook Centropomus ensiferus (9.80 ± 0.3 g, mean ± SE) were studied in order to evaluate the influence of salinity on physiological properties under rearing conditions. Growth performance, survival rates, and ion concentrations (Na⁺, K⁺, Cl^?) as well proximal composition were measured over 76 days. Fish were exposed to three experimental salinities (0, 10, 20 ‰ , three replicates per treatment) and maintained in plastic tanks with a recirculation system equipped with flow‐through aquaria pumps (533 L per tank). Fish were fed twice daily to apparent satiation; at the end of the experiment the weight of fish kept in 10 ‰ was higher than that of fish kept in 0 and 20 ‰ , however no significant differences (P > 0.05) were observed among the experimental salinities. Survival was significantly lower in 10 ‰ salinity than in fish kept in 20 and 0 ‰ salinities. No significant differences (P > 0.05) were found in the Condition factor (K), specific growth rate (SGR), or in plasma Na⁺, K⁺, or Cl^? concentrations among treatments. Salinities also did not affect body composition (P > 0.05), but were significantly lower (P < 0.05) than at the start of the experiment. However, towards the end of the experiment a large accumulation of visceral fat in fish farmed in the three salinities (VFI > 4%) was observed. Water quality was within the optimum range (T: 28.7 ± 0.1°C; O2: 5.6 ± 0.1 mg L^?1; ammonia: 0.2 mg L^?1) for the growth of swordspine snook. Data indicates that C. ensiferus is an ionoregulator fish and able to cultivate successfully in various osmotic conditions, and in turn, maintain high levels of survival in captivity.     

Protective effect of binaphthyl diselenide,a synthetic organoselenium compound,on 2‐nitropropane‐induced hepatotoxicity in rats

Organoselenides have been documented as promising pharmacological agents against a number of diseases associated with oxidative stress. Here we have investigated, for the first time, the potential antioxidant activity of binaphthyl diselenide ((NapSe)₂; 50 mg kg^?1, p.o.) against the 2‐nitropropane (2‐NP)‐induced hepatoxicity in rats, using different end points of toxicity (liver histopathology, plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatinine). In addition, in view of the association of oxidative stress with 2‐NP exposure, hepatic lipid peroxidation, ascorbic acid levels, δ‐aminolevulinate dehydratase (δ‐ALA‐D) and catalase (CAT) activities were evaluated. 2‐NP caused an increase of AST, ALT and hepatic lipid peroxidation. 2‐NP also caused hepatic histopathological alterations and δ‐ALA‐D inhibition. (NapSe)₂ (50 mg kg^?1) prevented 2‐NP‐induced changes in plasmatic ALT and AST activities and also prevented changes in hepatic histology, δ‐ALA‐D and lipid peroxidation. Results presented here indicate that the protective mechanism of (NapSe)₂ against 2‐NP hepatotoxicity is possibly linked to its antioxidant activity. Copyright © 2010 John Wiley & Sons, Ltd.     

Protective effects of antioxidant combination against D‐galactosamine‐induced kidney injury in rats

The protective effects of an antioxidant combination in kidney injury induced by the injection of D‐galactosamine (D‐GaIN) were examined in the present study. Sprague Dawley female rats were used and divided into four groups as follows: (1) animals injected physiological saline solution, intraperitoneally, (2) animals treated with the combination of ascorbic acid (100 mg kg^?1 day^?1), β‐carotene (15 mg kg^?1 day^?1), α‐tocopherol (100 mg kg^?1 day^?1), and sodium selenate (0.2 mg kg^?1 day^?1) for three days orally, (3) rats injected D‐GaIN (500 mg kg^?1) intraperitoneally as a single dose, and (4) animals treated with the antioxidant combination for three days, then injected D‐GaIN. The tissue and blood samples of animals were collected for morphological and biochemical evaluations. Histopathological injury in kidney tissues was observed together with a significant increase in tissue lipid peroxidation (LPO) level, myeloperoxidase (MPO), lactate dehydrogenase, catalase and superoxide dismutase (SOD) activities, and serum creatinine and urea levels, and a significant decrease in glutathione level and glutathione peroxidase activity in D‐GaIN injected rats. However, a decrease in the degenerative changes was detected in the kidney tissue of D‐GaIN + antioxidant group, and biochemical results showed reversed effects. In conclusion, it seems reasonable to conclude that the treatment of the antioxidant combination has a protective effect on D‐GaIN‐induced kidney injury of rats. Copyright © 2010 John Wiley & Sons, Ltd.     

Organochlorine pesticides in Muraena helena L. 1758 from the Eastern Adriatic Sea

This work examines the bioaccumulated organochlorine compounds in Muraena helena to draw attention to this species as a potential bioindicator organism. The morays were caught in the East Adriatic Sea, Elaphite Islands, near Dubrovnik, Croatia (lat: 42°45′38.8″; long: 17°45′53.6″) at the same location in summer (August, 2009) and winter (January, 2010), at depths from 5 to 10 m. Nine fish were caught by longline hooks per each field trip (total in summer and winter, N = 18). No single fish was free of organochlorines (OC), but not all pesticides were present in every fish. The concentration level was: Endrin > ppDDE > Heptachlor epoxide > Heptachlor > Aldrine > Lindane > βHCH > δHCH > Endrin aldehyde). Endrin was the only pesticide approaching the maximum concentrations proposed by the European Union and Croatia (summer max. concentration = 14.75 μg kg^?1; winter max. concentration = 8.35 μg kg^?1). All other pesticides ranged from 0.1 to 0.7 μg kg^?1. Heptachlor was absent in winter and δ‐HCH and Endrin aldehyde in summer, while Lindane and pp‐DDE had higher (P ≤ 0.05) concentrations in summer. Other residues had similar seasonal concentration levels. The p‐DDT was similar as in other biota from the Adriatic or Mediterranean. HCH concentrations corresponded to those found in organisms from the Italian area of the Adriatic. The endocrine and reproductive disrupting potential of the detected OCs are bases for future studies. Results show that morays are a good bioindicator model, with slight interspecies and seasonal variability in OC bioaccumulation as a consequence of diverse food consumption.     

Omega 3 chronic supplementation attenuates myocardial ischaemia‐reperfusion injury through reinforcement of antioxidant defense system in rats

Currently, controversial clinical data about the protective effects in the consumption of n‐3 polyunsaturated fatty acids (PUFAs) in ischaemic heart diseases exist. Improved myocardial resistance to ischaemia‐reperfusion (IR) injury results in non‐lethal myocardial infarction, which is a relevant factor in the myocardial function. We hypothesized that chronic supplementation with PUFAs reduced infarct size (IS) and induced an improvement on oxidative stress‐related parameters in IR model. Rats were supplemented with two doses of PUFAs D1 (n = 7) (0.6 g kg^?1 d^?1) and D2 (n = 7) (1.2 g kg^?1 d^?1) for 8 weeks. Control group (n = 7) received only standard diet. In ex vivo model, all rat hearts were subjected to 30 min of global ischaemia followed by 120 min of reperfusion. The IS and left ventricular function were assessed. Lipid peroxidation, reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio and antioxidant enzyme activity were measured in the whole heart. The results show a reduction in IS in a dose‐dependent manner with PUFAs D1 (30.6%) and D2 (48.5%) and higher values of left ventricular developed pressure, at the end of the reperfusion, for each dose, respectively (p < 0.05). The two PUFAs groups showed higher values of GSH/GSSG ratio and lipid peroxidation, and higher values of activity of antioxidant enzymes catalase, superoxide dismutase and glutathione peroxidase at basal condition (p < 0.05). At the end of reperfusion, the GSH/GSSG ratio and antioxidants enzyme activity did not show a significant drop in their values (p > 0.05). These findings suggested that the supplementation with PUFAs induces cardioprotection against IR injury, associated with reinforcement of the antioxidant defense system. Copyright © 2013 John Wiley & Sons, Ltd.     

The effects of different cycles of starvation and re‐feeding on growth and body composition in rainbow trout (Oncorhynchus mykiss,Walbaum, 1792)

This study was designed to investigate the effects of starvation and re‐feeding cycles on the growth performance and body chemical composition of Oncorhynchus mykiss juveniles. A total of 360 juveniles with initial mean weights (IW) of 8.46 ± 0.07 g (n = 360) were stocked into 400‐L tanks in triplicate for each group, with 30 juveniles per tanks. The control group received regular feed, as is the common practice. The three other groups were periodically starved: 1 day starvation followed by 6 days re‐feeding (S1), 2 days starvation followed by 5 days re‐feeding (S2) and 3 days starvation followed by 4 days re‐feeding (S3). The experiment lasted for 10 weeks, over the course of which the water flow rate was 4 L min^?1 and the water quality parameters determined as: temperature 14.4 ± 1.1°C, oxygen 8.2 ± 0.4 mg L^?1 and pH 7.5 ± 0.2. At the end of the study, S1 had the best growth performance (final weight, specific growth rate, average daily growth) of all test groups (P < 0.05). The lowest daily feed intake (DFI) and growth performance parameters were observed in S3 (P < 0.05), while protein efficiency ratio (PER), net protein utilization (NPU) and lipid efficiency ratio (LER) were higher in the S3 fish group than in the other groups (P < 0.05). Whole body protein and lipid contents were highest in S1 fish. The hepatosomatic index (HSI) and viscerosomatic index (VSI) were significantly different among groups (P < 0.05). Feed conversion ratio (FCR) was significantly lower in starvation groups S1, S2 and S3 than in the control (P < 0.05). Compensation coefficient (CC) values were higher than 1 in all starvation groups. The concluding indicate that rainbow trout exposed to 1 and 2 days of starvation in week cycles could achieve over compensation compared to the control. Additionally, partial growth compensation and improved feed utilization could be achieved in a starvation group within 3 days in a week, by beginning with the juvenile size over a 10‐week experimental period.     

Immune responses and intestinal morphology of striped catfish,Pangasianodon hypophthalmus (Sauvage, 1878), fed dietary nucleotides

The present study was conducted to evaluate the effects of dietary nucleotides (NT) on growth performance, immune responses, and intestinal morphology of striped catfish, Pangasianodon hypophthalmus. Different levels of NT (0, 0.25. 0.5, 0.75, and 1% weight per weight, WW^?1) were used in the basal diet and then randomly allocated to triplicate groups of fish with an average initial weight of 1.52 ± 0.11 g for 10 weeks. Nucleotide supplementation did not improve growth parameters significantly (P > 0.05). Feeding fish with a NT‐containing diet significantly improved ACH₅₀ activity and IgM levels in comparison to the control group (P < 0.05). The dietary NT (P < 0.05) affected the intestinal morphology, whereby the folds and enterocyte heights in the mid‐intestine were significantly increased compared to the control group (P < 0.05), while the microvilli length was not affected. The results indicate that feeding striped catfish with commercial NT have significant effects on the immune parameters and intestinal morphology of catfish and that the best NT levels are 0.25 and 0.5%.