Endogenous antioxidant systems of two teleost fish,the rainbow trout and the black bullhead,and the effect of age

Antioxidant enzyme activities and glutathione status were determined in different tissues of two teleost species, the rainbow trout (Oncorhynchus mykiss) and the black bullhead (Ameiurus melas) to establish whether age-related changes exist between mature and immature individuals. Glutathione reductase and superoxide dismutase activities were significantly lower in hepatic and extrahepatic tissues of 3+ year than 1+ year trout and bullheads. Activities of glutathione peroxidase, catalase and glutathione S-transferase did not exhibit a clear pattern, with decreases in liver and kidney, but increases in gill and muscle tissues. Glutathione concentrations were significantly higher in most tissues of 3+ year than in 1+ year trout, but remained unchanged or decreased in tissues of older bullheads. The results imply an age- or maturation-dependent effect on key antioxidant enzymes in various tissues of these 2 teleost species. Thus, age and maturation may impact upon the use of oxidative stress parameters as indicators of contaminant exposure in environmental studies.     

Oxidative stress parameters during starvation and refeeding periods in Adriatic sturgeon (Acipenser naccarii) and rainbow trout (Oncorhynchus mykiss)

This work analyses the changes in the redox balance in two fish species: Adriatic sturgeon ( Acipenser naccarii ) and rainbow trout ( Oncorhynchus mykiss ) during starvation and refeeding period. The starvation period raised the lipid peroxidation (thiobarbituric-acid-reacting substances) levels in liver and blood, while a decline occurred in the antioxidant enzymatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glutathione reductase (GR) in both fish species. In liver, after the refeeding period, SOD activity recovered in both species, whereas CAT activity recovered only in trout. Furthermore, in both tissues of the two species, the lipid peroxidation levels remained high after 2 months of refeeding. In white muscle and heart, the lipid peroxidation levels indicate that these tissues did not undergo oxidative stress during the 72-day period. During starvation, in the muscle of both fish the fall in the lipid peroxidation level coincided with a rise in CAT, GPX and GR. The refeeding period in this tissue raised the lipid peroxidation level, and the enzymatic activities reached the values of the first point of starvation. In heart, no oxidative damage was detected during starvation in either species. The CAT and SOD activities increased during the starvation period only in trout.     

Role of exogenous glutathione in teleost fish and its effects on antioxidant defense responses in rainbow trout exposed to 3,3',4,4'-tetrachlorobiphenyl

Intraperitoneal injection of glutathione (GSH) is shown to effectively increase tissue glutathione content in two teleost species, the rainbow trout and the American eel. GSH uptake into teleost tissues is a distinct piscine feature of GSH biochemistry compared with mammalian species where little or not uptake occurs of exogenously added GSH. Enhancement and depletion of tissue GSH status was used as a tool to examine the effects of altered GSH content on other cellular antioxidants in 3,3,4,4-tetrachlorobiphenyl (TCB) exposed rainbow trout. -Tocopherol content was unchanged and thiobarbituric acid reactive substances (TBARS), an indicator of lipid peroxidation, changed little in liver and muscle of trout exposed to TCB and the various GSH treatments. However, -tocopherol levels in muscle and superoxide dismutase activities in the various tissues were significantly higher in controls and TCB-saline treated fish than in GSH deficient and lipoate supplemented TCB exposed trout. GSH status thus appears to affect some cellular antioxidant defenses in TCB exposed trout.     

Revisiting redox-active antioxidant defenses in response to hypoxic challenge in both hypoxia-tolerant and hypoxia-sensitive fish species

It is not known whether changes in antioxidant levels always occur in fish in response to the oxidative stress that usually accompanies a hypoxic challenge. The studies of antioxidant responses to hypoxia in fish have mostly focused on very anoxia-tolerant species and indicate that there is an enhancement of antioxidant defenses. Here we present new data on redox-active antioxidants from three species, which range in their tolerance to hypoxia: the epaulette shark, threespine stickleback, and rainbow trout, together with a compilation of results from other studies that have measured oxidative stress parameters in hypoxia-exposed fish. The results suggest that in general, fish do not show an increase in redox-active antioxidant defense in response to oxidative stress associated with hypoxia. Rather, the changes in antioxidant defenses during hypoxia are very much species- and tissue-specific and are not linked to the level of hypoxia tolerance of the fish species.     

Antioxidant processes are affected in juvenile rainbow trout (Oncorhynchus mykiss) exposed to ozone and oxygen-supersaturated water

Two groups of juvenile rainbow trout (Oncorhynchus mykiss) were exposed for 4 h to either hyperoxic (>40 mg O₂/l) or ozonised (5.2 μg O₃/l) water containing supersaturated oxygen. Gill, liver, blood cells and plasma were taken 1, 5, 12, 24 and 48 h following the exposure periods and antioxidant responses and oxidative damage studied in terms of, respectively, antioxidant enzyme activities/glutathione status and lipid peroxidation. Observed biochemical changes were significant at p<0.05. Ozonation elevated oxidised glutathione (GSSG) levels, increased lipid peroxidation and decreased reduced glutathione (GSH) levels in gills 1 h following exposure, which indicate oxidative stress. However, the longer-term effects (48 h) following ozone exposure resulted in increased GSH levels in both gills and liver and, measured as oxidative stress index (OSI), were indicative of enhanced potential of tissues to resist oxidative stress. Ozonation also resulted in elevated activity of superoxide dismutase (SOD) at 5–12 h following exposure in gills compared to 24–48 h in liver, indicating either differential regulation and time-courses of response, or an earlier impact of ozonolysis products on gills than liver. In contrast, catalase activity was elevated in both gills and liver at 24 h by the effects of hyperoxia alone. Hyperoxia also decreased GSSG levels in both gills and liver, but had no effect on lipid peroxidation. Increases were seen in the activities of selenium-dependent glutathione peroxidase as a result of ozonation (gills; 5 and 24 h) and hyperoxia (liver; 1 h), and in total GPX (Se-dependent and independent) as a result of ozonation (both tissues; 48 h), but no effects were seen on glutathione reductase (GR) in either tissues. Levels of GSH were increased in blood cells at various times following hyperoxia. Overall, the results show (i) differential antioxidant and pro-oxidant effects of ozonation compared to hyperoxia, (ii) gills and possibly blood as the first line of impact and defence, with later effects on liver, and (iii) that even after 24–48 h following ozone exposure, all antioxidant defences had not returned to pre-exposure values.     

Alterations in iron, zinc and major plasma proteins of rainbow trout, Oncorhynchus mykiss (Walbaum), and brook trout, Salvelinus fontinalis (Mitchill), with sterile peritonitis induced by oil-adjuvanted multivalent bacterin vaccination

The early humoral responses of rainbow trout, Oncorhynchus mykiss (Walbaum), and brook trout, Salvelinus fontinalis (Mitchill), with sterile inflammation induced by intraperitoneal Lipogen Triple vaccination were compared to determine if genetic differences in susceptibility to furunculosis in salmonids correlated with different acute phase responses to vaccination. Similar severe acute sterile peritonitis occurred in response to Lipogen Triple in both species. Both species also had a rapid transient reduction in plasma iron concentration at 3 days. Moderate hypoferraemia persisted to day 14 in brook trout, but returned to normal by day 7 in rainbow trout. Plasma zinc decreased sharply 3 days after vaccination in rainbow trout and returned nearly to control levels by day 10; however, plasma zinc did not change in brook trout. Two-dimensional sodium dodecyl sulphate polyacrylamide electrophoresis of plasma proteins revealed that increased amounts of a 48-kDa protein group coincided with the hypoferraemic response in rainbow trout. In addition, a modest elevation in a 16-kDa protein group also occurred in rainbow trout. These studies demonstrated the rapid changes in plasma iron in both species and mild elevation of two putative acute phase plasma proteins associated with vaccine-induced inflammation in rainbow trout.     

Study of the Oxidative State,as a Marker of Welfare,on Gilthead Sea Bream,Sparus aurata,Subjected to Handling Stress

In this study, we investigated the effect of repeated handling on the oxidative state of gilthead sea bream, Sparus aurata. We determined the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPX), glutathione transferase (GST), and DT‐diaphorase (DTD) in liver, digestive tract, brain, gills, and white muscle. We also measured the lipid‐peroxidation level (malondialdehyde – MDA – concentration) and the glucose 6‐phosphate dehydrogenase activity (G6PDH). The results show that repeated low‐intensity handling on gilthead sea bream alter the oxidative status of tissues such as liver, digestive tract, and muscle in the last term can affect its welfare. The brain in a situation of handling stress is protected from oxidative damage by the activity of antioxidant enzymes. Finally, the concentration of MDA in tissues can be a good candidate as a biomarker of stress and welfare in fish.     

Biochemical and histological changes in the liver tissue of rainbow trout (Oncorhynchus mykiss) exposed to sub-lethal concentrations of diazinon

The organophosphate insecticide diazinon is widely used to control pest in Iran. The purpose of the present study was to investigate the antioxidant and histopathological changes in the liver tissue of rainbow trout (Oncorhynchus mykiss) exposed to 0.1 and 0.2 mg/L of a commercial formula of diazinon for a period of 28 days. Antioxidant enzyme activities—catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase—were determined after 7, 14 and 28 days of exposure. Histopathological analyses were performed at the 28th day. All antioxidant enzymes were induced after 7 days of diazinon treatment in both concentrations of diazinon. Catalase and superoxide dismutase maintained elevated activities during all the treatment period. Glutathione peroxidase activity returned to the control values at the 14th day, decreasing to values below control at the 28th day in both diazinon concentrations. Glutathione reductase maintained increased activities at the 14th day in the 0.1 mg/L diazinon, decreasing to control values at the 28th day. In the 0.2 mg/L group, the activity returned to control values at the 14th and decreased below the control at the 28th day. Total antioxidant capacity of hepatocytes significantly decreased in fishes exposed to diazinon during all experimental periods. Hypertrophy of hepatocytes, vacuolization of cell cytoplasm and hepatocyte cloudy swelling were observed in the liver tissue of fish exposed to both concentrations of diazinon. The results showed that diazinon altered the activity of antioxidant enzymes and the cellular total antioxidant capacity inducing oxidative stress and cellular damage in hepatocytes evidenced by histopathological analysis.     

Tissue-specific daily variation in the oxidative status of sturgeon (<Emphasis Type="Italic">Acipenser naccarii</Emphasis>) and rainbow trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>): a comparative study

The oxidative status is associated with animal lifespan, metabolism, activity and circadian rhythms. The objective of this work is to study the time course of the oxidative status over a daily cycle in the plasma, liver and brain, and the changes in the plasma cortisol levels of sturgeon and trout. The knowledge of daily oxidative status will provide a better understanding of the trout and sturgeon physiology and adequate maintenance and food supply of farmed fish in relation to photoperiod. Superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione transferase, DT-diaphorase activities, lipid peroxidation and cortisol were measured. Our results showed that the antioxidative enzyme activities and lipid peroxidation in the liver of trout and sturgeon changed through the day, with increased levels in lipid peroxidation of liver in the dark period for sturgeon. This could be related to the different activity time in both species, an issue to be taken into account when designing the guidelines of the maintenance of these species in fish farms. On the contrary, there was not clear influence of the daily rhythms on brain oxidative status. The higher efficiency of the antioxidant defences in the brain of sturgeon, which displays less lipid peroxidation and higher antioxidative activity, could be related to its longer life expectancy. The absence of any apparent daily rhythm in the plasma cortisol levels in sturgeon could indicate a lower susceptibility to stress, and that mechanisms involved in cortisol secretion in chondrosteans could be different from that described for teleosteans.     

Biomarkers of oxidative stress and antioxidant defences as indicators of different disinfectants exposure in the heart of rainbow trout (Oncorhynchus Mykiss Walbaum)

The aim of this study was to evaluate the impacts of different disinfectants' treatment using in aquaculture on the oxidative stress biomarkers such as thiobarbituric acid reactive substrates (TBARS) and carbonyl derivatives of protein oxidative modification, as well as antioxidant defences [superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and glutathione peroxidase (GPx) activity] and total antioxidant capacity (TAC) in the heart tissue of rainbow trout (Oncorhynchus mykiss). In the disinfectants exposure, fish were treated to chloramine‐T (final concentration 10 g m^?3), chloride dioxide (5 g m^?3), formalin (200 mL m^?3) and CIP disinfectant based on peracetic acid and hydrogen peroxide (16 mL m^?3) for 20 min and repeated three times every 3 days. Both chlorine dioxide and formalin treatment was indicated by a significant increase in the level of heart TBARS levels and carbonyl derivatives content and decreased SOD activity. Tissue oxidative stress biomarkers were unchanged upon chloramine‐T or CIP disinfectant exposure. Increased oxidative stress could modify antioxidant defences, principally causing increased CAT activity in the heart tissue of formalin‐ or ClO₂^?‐exposed fish. The correlation between oxidative stress biomarkers and GPx activity indicates that enzymes related to glutathione metabolism were responsible to formalin or ClO₂^?‐induced oxidative stress. Hence, TBARS, carbonyl derivatives and antioxidant defences could be used as biomarkers in evaluating the toxicity of formalin and chlorine dioxide using as disinfectants to trout.     

The role of nutritional factors in the prevention of peroxidative damage to tissues

The multi-level defence system present in vertebrate cells to protect against chain reactions initiated by free radicals (mainly toxic metabolites of oxygen) is outlined. It comprises superoxide dismutases (Cu-Zn and Mn dependent), glutathione peroxidase (Se dependent), vitamin E and glutathione S-transferase.The protective role of superoxide dismutase (SOD) was demonstrated by studies on trout (Salmo gairdneri) retina (Desrochers and Hoffert 1983). This tissue is subject to very high O₂ tensions but has a high resistance to O₂ toxicity that is dependent on a high dismutating capacity. The activities of both the cytosolic Cu-Zn SOD and the mitochondrial Mn SOD in the liver of rainbow trout were significantly altered in response to changes in dietary intake of these minerals.Deficiency of Se did not affect the growth rate of rainbow trout but led to greatly reduced activities of hepatic and plasma glutathione (GSH) peroxidase. There was no evidence of a Se-independent GSH peroxidase activity. In rainbow trout depleted of Se there was a compensatory increase in hepatic GSH S-transferase activity. This enzyme in conjunction with GSH has been shown to inhibit lipid peroxidation in the Festimulated microsomal systemin vitro. A dietary synergism between vitamin E and Se in rainbow trout has been demonstrated.The vitamin E requirement of rainbow trout is related to the polyunsaturated fatty acid (PUFA) content of the diet. The molar ratio PUFA: vitamin E in rainbow trout tissues is lower than that in rats. Time course studies on the uptake of orally administered vitamin E showed rapid incorporation into biomembranes; few differences between normal and vitamin E deficient fish were evident. The ester form of vitamin E was more slowly assimilated than the alcohol.     

Gastric uptake of recombinant growth hormone in rainbow trout

The aim of the present study was to investigate gastrointestinal uptake of recombinant growth hormone in rainbow trout. Recombinant human GH was used in this study to avoid cross reactivity with the endogenous trout GH molecule. Using both in vitro and in vivo approach, the results demonstrate that stomach is the main site of uptake for orally administered intact recombinant human growth hormone (hGH) in rainbow trout. The presence of hGH was verified by western blot analysis in the stomach tissue as well as in the serum after 30 minutes of intubation. No traces of the hGH could be detected after 90 minutes of administration, indicating rapid clearance of the hormone in rainbow trout. Furthermore, no immunoreactive hGH was detected in other tissues including mid-gut, muscle and liver at the time points tested. The findings provide novel information on the gastric uptake of hGH in rainbow trout, and would be of relevance to the application of GH in aquaculture.     

Elevated concentrations of T‐2 toxin cause oxidative stress in the rainbow trout (Oncorhynchus mykiss)

T‐2 toxin is a mycotoxin produced by several Fusarium fungi that can contaminate plant components used in feed for aquaculture. The aim of this 28‐day study was to investigate the effect of the T‐2 toxin in feed in concentrations 1.0 and 1.8 mg/kg (0.01 mg/kg b.w. and 0.018 mg/kg b.w.) on the oxidative stress markers and on the detoxifying enzymes of the rainbow trout. The results showed that T‐2 toxin in both tested concentrations induced oxidative stress and antioxidant defence in the liver of trout manifesting by the increase in activities of enzymes glutathione‐S‐transferase, glutathione reductase and glutathione peroxidase and the decrease in the catalase activity. The increase in lipid peroxidation was recorded only in the higher concentration of T‐2 toxin. Ceruloplasmin activity in the plasma increased at both tested concentrations, and the ferric reducing ability of the plasma increased at the higher toxin concentration. The T‐2 toxin in feed caused alteration of the total protein, albumin and triacylglycerols as well as the alkaline phosphatase activity in the plasma. Despite no changes in histological examination were found, the influence of T‐2 toxin on scavenger system may result in increased sensitivity to other stress factors.     

The protective effects of Vitamin C and Trolox on kinematic and oxidative stress indices in rainbow trout sperm cells against flower‐like ZnO nanoparticles

This study investigated the protective effects of 1 mM Vitamin C and 1 mM Trolox on kinematic and oxidative stresses in rainbow trout (Oncorhynchus mykiss) sperm cells against flower‐like zinc oxide nanoparticles (ZnO‐NP, 1 mg/L) in vitro, during 2 hr. Trolox showed protective effects on all kinematic parameters measured for sperm cells against ZnO‐NPs, whereas Vitamin C only affected angular path velocity (VAP), linearity (LIN) and amplitude of lateral displacement of the sperm cell head (ALH). Although ZnO‐NPs reduced total glutathione (TGSH) and catalase (CAT) compared with the control, there were positive treatment effects for both Trolox and Vitamin C on antioxidant capacity. Conversely, while ZnO‐NP increased the rate of malondialdehyde (MDA) lipid peroxidation, it decreased following antioxidant therapy. This research suggests that Trolox and Vitamin C play a protective role for rainbow trout sperm exposed to ZnO‐NP.     

Effects of dietary selenium of organic form against lead toxicity on the antioxidant system in Cyprinus carpio

In this study was evaluated potential protective effect of organic selenium (Se) on heavy metal stress induced by lead (Pb) in Cyprinus carpio. For this reason, C. carpio was exposed to sublethal concentration of Pb (1.5 mg/L Pb(NO₃)₂) for 14 days. The fish were fed a basal (control; measured 0.55 mg/kg Se) diet or a basal diet supplemented with 2.50 mg/kg (measured 2.92 mg/kg Se) organic Se (Sel-Plex^®) during the experiment period. The variations in glutathione peroxidase (GSH-Px), glutathione S-transferase (GST) activities, and levels of reduced glutathione (GSH) with malondialdehyde (MDA) in liver and brain tissues of C. carpio were investigated in experimental groups. GSH levels in liver and brain tissues were significantly decreased by exposure to Pb. GST activity was significantly increased (p < 0.05) in liver tissue, but decreased in brain of treated fish by exposure to Pb. Also, GSH-Px activity was significantly increased in liver tissue, but decreased in brain of Pb-treated fish. Levels of MDA were increased in liver and brain of Pb-treated fish. The organic Se treatment for Pb-intoxicated animals improved activities of GSH-Px, GST and levels of MDA within normal limits. Supplemented Se could be able to improve Pb-induced oxidative stress by decreasing lipid peroxidation and regulating antioxidant defense system in tissues.     

Hsp60/10 and sHsp families of heat shock protein genes in rainbow trout (Oncorhynchus mykiss) and their expression under heat stress

Heat shock proteins (Hsps) are highly conserved proteins whose expression can be induced by high temperature and play an important role in a variety of biological processes. However, systematic identification of the Hsp60/10 and small Hsp (sHsp) gene family in rainbow trout has not yet been reported, and there is little available information about its roles in evolution in rainbow trout, a typical economical cold-water fish. In this study, we performed a comprehensive analysis of the rainbow trout Hsp60/10 and sHsp gene family and to investigate their expression profiles. A total of one Hsp60 gene, one Hsp10 gene, and ten sHsp genes were identified. According to RNA-seq analysis of rainbow trout liver and head kidney under heat stress, a total of six out of ten sHsp genes were significantly upregulated in liver and head kidney. Real-time RT-PCR (RT-qPCR) was used to quantitatively analyze the expression levels of these genes in different tissues of rainbow trout. Results showed that the expression of hspe1 and hspd1 was lowest in liver and gill, respectively, and highest in brain. In sHsp gene family, all genes are highly expressed in the liver and head kidney, but relatively low in the heart, spleen, brain, gills, and muscles. This systematic analysis provided valuable information about the diverse roles of Hsp60/10 and sHsp in the evolution of teleost fish, which will contribute to the functional characterization of Hsp60/10 and sHsp genes in further research.

     

Effect of dietary macronutrient proportion on intermediate metabolism and oxidative status in sturgeon (<Emphasis Type="Italic">Acipenser naccarii</Emphasis>) and trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>): comparative study

Three isoenergetic diets varying the proportion of dietary energy supplied by each of the macronutrients (carbohydrate, lipid, or protein) were delivered, to farmed sturgeon (Acipenser naccarii) and trout (Oncorhynchus mykiss), to test the possible effects on the intermediate metabolism and oxidative status in liver, white muscle, and heart. In trout, there is an adaptive metabolic response to an increase in lipids and carbohydrates in the diet. However, this does not happen in the sturgeon. These differences may be due to different dietary habits of both species. In terms of oxidative status, only the liver displayed oxidative stress in both species, showing an increase in the lipid peroxidation and antioxidant enzyme activities after feeding with the high-lipid and high-protein diet.     

虾青素和角黄素对虹鳟肌肉着色和肝脏总抗氧化能力的影响

分别在基础饲料(对照组)中添加100 mg/kg的虾青素、角黄素,混合色素(50 mg/kg虾青素+50 mg/kg角黄素)饲喂初始体重为(56.60±0.63) g的虹鳟60 d,考察虾青素和角黄素对虹鳟肌肉着色和肝脏总抗氧化能力的影响。结果显示,饲料中添加了虾青素、角黄素和混合色素后对虹鳟增重率、饲料系数及肌肉常规成分、肌肉失水率、含肉率均无显著影响(P> 0.05)。虾青素组、角黄素组和混合色素组虹鳟肌肉的比色卡得分、红度、虾青素含量和血清总类胡萝卜素含量均比对照组有显著提高(P< 0.05);虾青素组虹鳟肌肉比色卡得分(26.25)和红度值(18.40)显著高于角黄素组(22.38, 14.13)和混合色素组(24.00, 15.70)(P< 0.05);虾青素组虹鳟肌肉虾青素含量为4.75 mg/kg (30 d)和6.45 mg/kg (60 d),均显著高于混合色素组的3.87 mg/kg (30 d)和5.48 mg/kg (60 d)(P< 0.05);在虹鳟血清总类胡萝卜素含量方面,虾青素组 > 混合色素组 > 角黄素组;虾青素组、角黄素组、混合色素组虹鳟肝脏的总抗氧化能力之间无显著差异(P> 0.05),分别为2.39 U/mg,2.25 U/mg,2.39 U/mg,均较对照组(2.03 U/mg)显著提高(P< 0.05)。上述结果表明：饲料中添加100 mg/kg虾青素、角黄素及虾青素+角黄素混合(1∶1)均能有效改善虹鳟肌肉颜色,提高肝脏总抗氧化能力,虾青素、虾青素+角黄素混合(1∶1)对虹鳟肌肉的着色效果优于角黄素。     

Dietary profile of n‐3 series LC‐PUFAs in rainbow trout under regular stripping condition: Semen production and quality,hepato‐somatic index,haemato‐immunologic values,oxidative stress and fatty acid composition of liver,muscle and semen

In this study, the semen production and quality, hepato‐somatic index, haemato‐immunologic values, oxidative stress and the fatty acid contents in liver, muscle and semen of rainbow trout fed diets supplemented n‐3 series long‐chain polyunsaturated fatty acids (LC‐PUFAs) under regular stripping condition were investigated. For this aim, three diets (Control, D1 and D2) were prepared. These diets were contained n‐3 LC‐PUFAs (as a percentage of dietary total fatty acid) at 3.14%, 7.84% and 13.63% respectively. Experimental fish were fed with the control and test diets. The highest hepato‐somatic index, spermatologic (semen pH and volume, sperm motility and density), haematologic (haematocrit value, haemoglobin, erythrocyte count, corpuscular volume, haemoglobin and its concentration in corpuscular), immunologic (nitroblue tetrazolium activity, leucocyte count, phagocytic index, protein and immunoglobulin [IgM] in total plasma) and antioxidants (reduced glutathione, catalase, glutathione peroxidase and superoxide dismutase) values were found in fish fed the D2, D1 and control diets respectively (p < 0.01). Increase in the dietary n‐3 LC‐PUFAs was not significantly (p > 0.01) increased the oxidative stress (malondialdehyde) in fish. The results indicated that the n‐3 LC‐PUFAs at 13.63% level of total fatty acid in the diet could increase the semen production and quality, hepato‐somatic index, haematologic and immunologic values, and the n‐3 LC‐PUFA contents in liver, muscle and semen of rainbow trout broodstock under regular stripping condition.     

芬兰虹鳟鱼同工酶分析

运用聚丙烯酰胺凝胶电泳法对芬兰虹鳟肌肉(M)、心(H)、肝(L)、肾(K)、眼(E)等5种组织中的乳酸脱氢酶(LDH)、乙醇脱氢酶(ADH)、苹果酸酶(ME)、葡萄糖-6-磷酸脱氢酶(G6PDH)、过氧化物酶(POD)和酯酶(EST)进行了初步研究,并对各种酶的同工酶位点及酶谱表型进行分析。结果表明,除酯酶外,其他5种同工酶均表现出不同程度的组织特异性。同工酶表型种群遗传学研究发现,6种同工酶共记录15个基因座位,多态座位比例(P=40%)略高,位点有效等位基因数(Ne=1.4)较大,表明芬兰虹鳟种群遗传多样性偏高。