眼针对VD大鼠学习记忆障碍及SODMDA检验指标的影响

目的:探讨眼针对血管性痴呆(VD)大鼠学习记忆障碍、血清过氧化酶歧化物(SOD)活性及丙二醛(MDA)含量的影响.方法:4-血管阻断法制成血管性痴呆大鼠模型.取眼针肝区、心区、肾区.共治疗30天,并与西药尼莫通组相对照.实验前后分别进行Y-型迷宫测试及实验结束后腹主动脉取血测量血清SOD活性及MDA含量.结果:与对照组比较,模型组大鼠学习记忆明显障碍,眼针组、尼莫通组与模型组比较明显改善学习记忆能力(P＜0.01).模型组术后血清中SOD活性降低、MDA含量升高.眼针组、尼莫通组与模型组比较有显著差异(P＜0.01).结论:眼针疗法可改善实验性血管性痴呆大鼠学习记忆障碍及提高血清中SOD活性、降低MDA含量.

Occurrences of Yttrium in Soil and Its Potential Impacts on Paddy Rice Triticum aestivum

[Objective] The effects of yttrium nitrate （YNO3） on biomass and antioxi- dant systems of paddy rice （Yttrium （Y）; Oxidative stress; Dismutases （SOD）; Per- oxidases （POD）, Catalases （CAT）, Paddy rice （Triticum aestivum）） together with the occurrences of Y in soils were investigated to assess its ecotoxicological effects on plant. [Method]Y solutions with various concentrations were sprinkled on soil sam- ples, which were well mixed and then put into culture dishes to culture paddy rice seeds for further evaluation. [Result] The results indicated that 25-100 mg/kg Y treatments significantly increased the biomass （total weight, root weight, shoot weight and leaf weight）, chlorophyll （CHL） content and protein content of paddy rice, whereas 200-800 mg/kg Y treatments had a converse effect. Similarly, biomarker for the antioxidant systems including superoxide dismutases （SOD）, peroxidases （POD） and catalases （CAT） all exhibited similar trends in both shoots and roots of paddy rice. At the same time, the malonaldehyde （MDA） content increased at from 25 to 100 mg/kg and decreased with concentrations of Y from 100 to 800 mg/kg in both shoots and roots of paddy rice. This indicated that Y could stimulate the growth of plant at low concentration, but inhibit the growth at relatively high concen- tration. [Conclusion] The levels of Y were 641＋49, 328_＋16 and 473_＋40 mg/kg in soils collected from mining area, farmland and navel orange orchard respectively. The levels of Y in the investigated area were higher than the benefit level （100 mg/kg）, which could cause low biomass as well as low activity of SOD, POD and CAT in paddy rice. Therefore, a more careful use of Y is necessary in crop management.

Analysis of Amylase and Superoxide Dismutase Isozymes During the Germination Process of Emmenopterys henryi Oliv Seeds

[ Objective] The study was to understand the changes of amylase（AMY） and superoxide dismutase（SOD） isozymes during the ger- mination process of Emmenopterys henryi Oliv seeds. [ Metbod] By employing polyacrylamide gel electrophoresis method, the expressions of AMY and SOD isozymes during seed germination process were analyzed. ~ Result] The main AMY bands remained strong during the whole peri- od and a new band A2 appeared in the middle and late period of seed germination. Some new SOD bands occurred at the early stage, then be- came weak or disappeared in the middle period, and band S6 became intense in the late peried. [ Conclusion.] The expression of AMY and SOD isozyme gene has temporal difference during germination of E. henryi Oliv seeds.

Relationship between the Hypersensitive Response of Wheat to Blumeria graminis f. sp. tritici and Hydrogen Peroxide,Three Enzyme Activities Changes

[Objective] The research aimed to study the relationship between the hypersensitive response of wheat to Blumeria graminis f.sp.tritici and hydrogen peroxide,3 enzyme activities changes and lay the foundation for discussing the resistant physiological mechanism of wheat to B.graminis.[Method] Taking B.graminis Bgt 17 and Bgt 6 and wheat cultivar Yang 158 as test materials,the number of hypersensitive cells and activities of POD,PPO and SOD in wheat leaves treated by H2O2 were determined.[Result] The mastoid...

Effects of penehyclidine hydrochloride in small intestinal damage caused by limb ischemia-reperfusion

AIM:To investigate the protective effect of penehyclidine hydrochloride post-conditioning in the damage to the barrier function of the small intestinal mucosa caused by limb ischemia-reperfusion(LIR) injury. METHODS:Male Wistar rats were randomly divided into three groups(36 rats each) :the sham-operation group(group S) ,lower limb ischemia-reperfusion group(group LIR) ,and penehyclidine hydrochloride postconditioning group(group PHC) .Each group was divided into subgroups(n=6 in each group) according to ischemic-reperfusion time,i.e.immediately 0 h(T1) ,1 h(T2) ,3 h(T3) ,6 h(T4) ,12 h(T5) ,and 24 h(T6) .Bilateral hind-limb ischemia was induced by rubber band application proximal to the level of the greater trochanter for 3 h.In group PHC,0.15 mg/kg of penehyclidine hydrochloride was injected into the tail vein immediately after 3 h of bilateral hind-limb ischemia.The designated rats were sacrificed at different time-points of reperfusion;diamine oxidase(DAO) ,superoxide dismutase(SOD) activity,myeloperoxidase(MPO) of small intestinal tissue,plasma endotoxin,DAO,tumor necrosis factor-α(TNF-α) ,and interleukin(IL) -10 in serum were detected in the rats. RESULTS:The pathological changes in the small intestine were observed under light microscope.The levels of MPO,endotoxin,serum DAO,and IL-10 at T1-T6,and TNF-αlevel at T1-T4 increased in groups LIR and PHC(P<0.05) compared with those in group S,but tissue DAO and SOD activity at T1-T6 decreased(P<0.05) .In group PHC,the tissue DAO and SOD activity at T2-T6,and IL-10 at T2-T5 increased to higher levels than those in group LIR(P<0.05) ;however,the levels of MPO,endotoxin,and DAO in the blood at T2-T6,and TNF-αat T2 and T4 decreased(P<0.05) . CONCLUSION:Penehyclidine hydrochloride post-conditioning may reduce the permeability of the small intestines after LIR.Its protection mechanisms may be related to inhibiting oxygen free radicals and inflammatory cytokines for organ damage.

Oxidative stress and hypoxia-induced factor 1α expression in gastric ischemia

AIM:To investigate the relation of reactive oxygen species (ROS) to hypoxia induced factor 1α (HIF-1α) in gastric ischemia. METHODS:The animal model of gastric ischemia reperfusion was established by placing an elastic rubber band on the proximal part of the bilateral lower limb for ligature for 3 h and reperfusion for 0,1,3,6,12 or 24 h. Ischemic post-conditioning,three cycles of 30-s reperfusion and 30-s femoral aortic reocclusion were conducted before reperfusion. Histological and immunohistochemical methods were used to assess the gastric oxidative damage and the expression of HIF1-α in gastric ischemia. The malondialdehyde (MDA) content and superoxide dismutase (SOD),xanthine oxidase (XOD) and myeloperoxidase (MPO) activities were determined by colorimetric assays. RESULTS:Ischemic post-conditioning can reduce post-ischemic oxidative stress and the expression of HIF-1α of gastric tissue resulting from limb ischemia reperfusion injury. MDA,SOD,XOD and MPO were regarded as indexes for mucosal injuries from ROS,and ROS was found to affect the expression of HIF-1α under gastric ischemic conditions. CONCLUSION:ROS affects HIF-1α expression under gastric ischemic conditions induced by limb ischemia reperfusion injury. Therefore,ROS can regulate HIF-1α expression in gastric ischemia.

The influence of cadmium on the antioxidant enzyme activities in polychaete Perinereis aibuhitensis Grube(Annelida:Polychaeta)

The infaunal polychaete Perinereis aibuhitensis Grube,distributed widely along Asian coasts and estuaries,is considered a useful animal model in ecotoxicological tests and a promising candidate in biomonitoring programs.This paper deals with the activities of antioxidant enzymes including superoxide dismutase(SOD),catalase(CAT),and glutathione peroxidases(GSH-Px) in infaunal polychaete P.aibuhitensis exposed to a series of sublethal water-bound cadmium(Cd) concentrations(0,0.34,1.72,3.44,6.89,and 17.22 mg L-1) under a short-term exposure(1-8 d).The results indicate that the SOD and GSH-Px activities in P.aibuhitensis are stimulated first and then renewed to the original level.The CAT activity of worms decreases at an earlier exposure time but increases to the control values at a later exposure time.Our study suggests that Cd can interfere with the antioxidant defense system of P.aibuhitensis.However,the changes in antioxidant enzyme activities for this species do not show the best promise as biomarkers in Cd biomonitoring of estuarine and coastal zones because weak or non-dose-effect relationships between the antioxidant enzymes activities and Cd levels are found.

Chitosan Oligosaccharide-Ca Complex Accelerates the Depuration of Cadmium from Chlamys ferrari

This study investigated the effect of a chitosan oligosaccharide-Ca complex (COS-Ca) on the depuration of cadmium (Cd) from Chlamys ferrari. After exposure to 0.5 mg L-1 CdCl2 for 3 or 7 d, the scallops were treated by COS-Ca prior to determina-tion of Cd, calcium (Ca) and zinc (Zn) contents, Cd distribution in organs, malondialdehyde (MDA) content and antioxidant variables. Results showed that COS-Ca reduced Cd content in the viscera of the scallops, with highest Cd depuration rate (47%) observed on day 3. The COS-Ca concentration substantially affected Cd depuration, and the exposure to 8.75 mg L-1 COS-Ca led to significantly higher Cd depuration rate compared with those of lower COS-Ca concentrations (1.75, 3.5, 5.25, and 7.00 mg L-1). Distribution analysis of Cd in scallop organs indicated that COS-Ca significantly reduced Cd content in the kidney throughout the 5-d experiment, as well as in the gill during the early stage of Cd depuration. In addition, COS-Ca treatment decreased glutathione peroxidase (GSH-Px) activity and MDA content while increasing superoxide dismutase (SOD) and catalase (CAT) activities on different days. Our work suggested COS-Ca complex treatment as an effective method for acceleration of Cd depuration from Cd-contaminated bivalves.

Effects of benzo(a)pyrene exposure on the antioxidant enzyme activity of scallop Chlamys farreri

Scallop Chlamys farreri was exposed to different concentrations of benzo(a)pyrene (BaP) (0.5 μg/L, 1.0 μg/L, 10.0 μg/L and 50.0 μg/L) for 30 days in seawater. The 7-ethoxyresorufin O-deethylase (EROD) activity was significantly induced, and increased with the increasing BaP concentration. The glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase (GPx) activities increased in short time at low concentration of BaP, and was significantly depressed at high concentrations. Scallop gill was more sensitive to BaP than the digestive gland, and the digestive gland was the main tissue to deal with oxyradicals. The contents of malondialdehyde (MDA) increased with the exposure time and there was a positive correlation (concentration-effect) between the MDA content and the concentration of BaP. The biomarkers determined in this experiment had important roles in detoxification, and showed great potential as biomarkers for oxidative stress. Controlled laboratory experiments designed to simulate field exposure scenarios are particularly useful in ascertaining biomarkers suitable for use with complex contaminant mixtures in the marine environment.

The Antioxidant Effects of Complexes of Tilapia Fish Skin Collagen and Different Marine Oligosaccharides

An excess of reactive oxygen species（ROS）leads to a variety of chronic health problems.As potent antioxidants,marine bioactive extracts containing oligosaccharides and peptides have been extensively studied.Recently,there is a growing interest in protein-polysaccharide complexes because of their potential uses in pharmaceutical and food industries.However,only few studies are available on the antioxidant activities of such complexes,in terms of their ROS scavenging capability.In this study,we combined and superoxide radicals,and to evaluate the influences on the activities of superoxide dismutase（SOD）,glutathione peroxidase（GSH-Px）and the level of malondialdehyde（MDA）in UV-induced photoaging models.The results indicated that the antioxidant activities of all the complexes were stronger than those of their individual components.Among the 11 complexes tested,two complexes,namely MA1000＋CP and κ-ca3000＋CP,turned out to be highly effective antioxidants.Although the detailed mechanisms of this improved scavenging ability are not fully understood,this work provides insights into the design of highly efficient peptide-oligosaccharide complexes for potential applications in pharmaceutical,cosmetics and food industries.

Proteasome inhibitor treatment in alcoholic liver disease

Oxidative stress, generated by chronic ethanol consumption, is a major cause of hepatotoxicity and liver injury. Increased production of oxygen-derived free radicals due to ethanol metabolism by CYP2E1 is principally located in the cytoplasm and in the mitochondria, which does not only injure liver cells, but also other vital organs, such as the heart and the brain. Therefore, there is a need for better treatment to enhance the antioxidant response elements. To date, there is no established treatment to attenuate high levels of oxidative stress in the liver of alcoholic patients. To block this oxidative stress, proteasome inhibitor treatment has been found to significantly enhance the antioxidant response elements of hepatocytes exposed to ethanol. Recent studies have shown in an experimental model of alcoholic liver disease that proteasome inhibitor treatment at low dose has cytoprotective effects against ethanol-induced oxidative stress and liver steatosis. The beneficial effects of proteasome inhibitor treatment against oxidative stress occurred because antioxidant response elements （glutathione peroxidase 2, superoxide dismutase 2, glutathione synthetase, glutathione reductase, and GCLC） were upregulated when rats fed alcohol were treated with a low dose of PS-34Z （Bortezomib, Velcade）. This is an important finding because proteasome inhibitor treatment up-regulated reactive oxygen species removal and glutathione recycling enzymes, while ethanol feeding alone down-regulated these antioxidant elements. For the first time, it was shown that proteasome inhibition by a highly specific and reversible inhibitor is different from the chronic ethanol feeding-induced proteasome inhibition. As previously shown by our group, chronic ethanol feeding causes a complex dysfunction in the ubiquitin proteasome pathway, which affects the proteasome system, as well as the ubiquitination system. The beneficial effects of proteasome inhibitor treatment in alcoholic liver disease are related to proteasome inhibitor reversibility and the rebound of proteasome activity 72 h post PS-341 administration.

Effects of dietary menadione on the activity of antioxidant enzymes in abalone, Haliotis discus hannai Ino

A 240-day growth experiment in a re-circulating water system was conducted to investigate the effects of dietary menadione on the growth and antioxidant responses of abalone Haliotis discus hannai Ino. Triplicate groups of juvenile abalone (initial weight: 1.19 ± 0.01 g; shell length: 19.23 ± 0.01 mm) were fed to satiation with 3 semi-purified diets containing 0, 10, and 1 000 mg menadione sodium bisulfite (MSB)/kg, respectively. Results show that there were no significant differences in the rate of weight gain or in the daily increment in shell length of abalone among different treatments. Activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione S-transferase (GST) and glutathione reductase (GR) in viscera were significantly decreased with dietary menadione. However, activities of these enzymes except for GPX in muscle were increased. Therefore, antioxidant responses of abalone were increased in muscle and decreased in viscera by dietary menadione.

Mercury (Hg^(2+)) effect on enzyme activities and hepatopancreas histostructures of juvenile Chinese mitten crab Eriocheir sinensis

We studied the effects of mercury (Hg2+) on antioxidant and digestive enzyme activities in terms of LC50 value and on hepatopancreas histostructures of juvenile Chinese mitten crabs Eriocheir sinensis in 40-day exposure to various concentrations of Hg2+ (0, 0.01, 0.05, 0.10, 0.20, and 0.30 mg/L). The results show that the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) significantly increased in the concentrations of 0.01 and 0.05 mg/L, while that of enzyme decreased in 0.10, 0.20 and 0.30 mg/L treatments. Meanwhile, Hg2+ disrupted the histostructures of the hepatopancreas, causing decreases in activities of pepsin, tryptase, amylase, and cellulose, which are synthesized in the hepatopancreas. Moreover, as the Hg2+ concentration increased, the survival rate of the crabs decreased, worst at 56.57% in 0.30 mg/L. Therefore, although crabs are able to tolerate low levels of mercury pollution, high levels lead to cellular injury and tissue damage in hepatopancreas, which then loses some of its vital physiological functions such as absorption, storage, and secretion.

PROTECTIVE EFFECT OF TETRAMETHYLPYRAZINE ON LEARNING AND MEMORY FUNCTION IN D-GALACTOSE-LESIONED MICE

To explore the protective effect of tetramethylpyrazine (TMP) on the learning and memory function in D-galactose (D-gal)-lesioned mice. Methods C57BL/6 mice were injected (s.c.) 2% D-gal for 40 days (100 mg·kg-1·d-1). Normal saline, TMP, and Huper-zine A were respectively given by intragastric administration in different groups from the third week. Learning and memory ability was tested with Morris water maze for 5 days at the sixth week. After completion of behavioral test, the mice were sacrificed by decapitation. The brain was rapidly removed, and the cortex and hippocampus were separated. The superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in the cortex were determined. At the same time, the activity of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE), the binding sites (Bmax) and the affinity (KD) of M-cholinergic receptor in the cortex, and Bmax and KD of N-methyl-D-aspartate (NMDA) receptor in the hippocampus were determined. Results In this model group, (1) The deficit of learning and memory ability, (2) elevated MDA content and lowered SOD activity, (3) decreased AChE activity and M-cholinergic receptor binding sites in the cortex, and (4) lowered NMDA receptor binding sites were observed in the hippocampus, as compared with the normal control. TMP could markedly (1) attenuate cognitive dysfunction, (2) lower MDA content and elevate SOD activity, (3) increase the activity of ChAT and AChE, and M-cholinergic receptor binding sites in the cortex in the mice treated with D-gal. NMDA receptor binding sites were also increased in the hippocampus in the treated mice. Conclusion TMP can significantly strengthen antioxidative function, improve central cholinergic system function, protect NMDA receptor activity, and thus enhance the learning and memory ability in D-gal-lesioned mice.

Growth and antioxidant status of oriental river prawn Macrobrachium nipponense fed with diets containing vitamin E

A feeding trial was carried out to investigate the dietary vitamin E requirement of the oriental river prawn Macrobrachium nipponense(weight of 0.3–0.4 g) and its effect role on antioxidant activity.Prawns were fed with seven levels of vitamin E(0,25,50,75,100,200,and 400 mg/kg diet) for 60 days.The results show that dietary vitamin E supplementation could significantly increased the prawn weight( P <0.05).The activity of superoxide dismutase(SOD) in the hepatopancreas was significantly higher in prawns fed with diets supplemented with ≤75 mg/kg vitamin E than in those fed with diets supplemented with 100–400 mg/kg vitamin E( P <0.05).The activity of catalase(CAT) in the hepatopancreas decreased significantly as dietary vitamin E supplementation increased( P <0.05),and no significant difference was detected in glutathione peroxidase(GSH-Px) activity between different dietary groups( P >0.05).The contents of vitamin E in the hepatopancreas and in the muscle increased with increasing dietary vitamin E.There was a linear correlation between the vitamin E level in diet and that in muscle,and between the vitamin E level in diet and that in the hepatopancreas.All the above results indicated that dietary vitamin E can be stored in the hepatopancreas and muscle and lower both the activities of SOD and CAT in the hepatopancreas,suggesting that it is a potential antioxidant in M.nipponense.Broken line analysis conducted on the weight gains of prawns in each diet group showed that the dietary vitamin E requirement for maximum growth is 94.10 mg/kg.

Effect of superoxide dismutase and malondialdehyde metabolic changes on carcinogenesis of gastric carcinoma

AIM： To investigate the relationship between the superoxide dismutase （SOD）, malondialdehyde （MDA） metabolic changes and the gastric carcinogenesis.METHODS： The SOD activity and MDA content were measured in the gastric tissues from the focus center, peripheral and far-end areas of gastric carcinoma （n = 52） arid gastric ulcer （n = 10）. All the tissues were subjected to routine histological examinations and classifications.RESULTS： The SOD activity was greatly reduced but the MDA content was markedly increased in the center areas of the non-mucous gastric carcinoma （non-MGC）; and the poorly differentiated gastric carcinoma varied. The SOD activity was gradually decreased and the MDA content was gradually increased in the tissues from the focus far-end, peripheral to center areas of non-MGC. Both of the SOD activity and the MDA content were significantly declined and were respectively at same low level in the tissues from the focus center, peripheral, and far-end area with the mucous gastric carcinoma （MGC）. In contrast to the gastric ulcer and grade I or II of non-MGC, the same level of the SOD activity and the MDA content were found in the focus center areas. Between non-MGC （groups A-D） and gastric ulcer （group F）, the differences of SOD activity and MDA content were very noticeable in the gastric tissues from the focus peripheral and far-end areas, in which the SOD activity showed noticeable increase and the MDA content showed noticeable decreasein the gastric ulcer.CONCLUSION： The active free radical reaction in the gastric tissues can induce the carcinogenesis of non-MGC. The utmost low ability of antioxidation in the gastric tissues can induce the carcinogenesis of MGC. The metabolic change of the free radicals centralized mostly in the center of ulcerated lesions only, which suggested the ability of antioxidation was declined only in these lesions. However, the metabolism of free radicals varied significantly and the ability of antioxidation declined not only in the local focus area but also in the abroad gastric tissues with gastric carcinoma.

Role of PGC-1αin muscle function and aging

This article focuses on the current underlying of molecular mechanisms of the peroxisome proliferator-activated receptor-γ coactivator-1α （PGC-1α） mediated pathway and discuss possible therapeutic benefits of increased mitochondrial biogenesis in compensating for mitochondrial dysfunction and ameliorating aging and aging-related diseases. PGC-1α is the master transcription regulator that stimulates mitochondrial biogenesis, by upregulating nuclear respiratory factors and mitochondrial transcription factor A, leading to increased mitochondrial DNA replication and gene transcription. PGC-1α also regulates cellular oxidant-antioxidant homeostasis by stimulating the gene expression of superoxide dismutase-2, catalase, glutathione peroxidase 1, and uncoupling protein. Recent reports from muscle-specific PGC-1α overexpression underline the benefit of PGC-1α in muscle atrophy and sarcopenia, during which PGC-1α enhanced mitochondrial biogenic pathway and reduced oxidative damage. Thus, PGC-1α seems to have a protective role against aging associated skeletal muscle deterioration.

Biological activities of a neutral water-soluble agar polysaccharide prepared by agarase degradation

Depolymerization of agar was performed using agarase, which was extracted from the cell-free medium of a culture of marine bacterial Alterornonas sp. nov. SY 37-12. After ethanol fractionation and lyophilization, the water-soluble agar polysaccharide （WSAP3） was collected. The anti-tumor activity of the product was determined by using Sarcoma 180 tumor in mouse. The tumor inhibition rate of WSAP3 the product was determined by using Sarcoma 180 tumor in mouse. The tumor inhibition rate of WSAP3 reached 48.7% at a dose of 64mg kg^-1 after 15 days treatment. WSAP3 enhanced the aetivities of superoxide dismutase and catalase, which suggests that WSAP3 was effective in promoting the antioxidation ability and eliminating danger from free radicals. The result of flow cytometry showed that the WSAP3 had no activities of cell cycle inhibition or apoptosis-inducing activities. The anti-oxidation of WSAP3 was further confirmed by test in vitro, which might play an important role in anti-tumor activity. The immunological regulation of WSAP3, especially its effect on the phagocytosis ratio and phagocytosis index of rophage was also assayed in test in vivo.

Homology modeling and evolutionary trace analysis of superoxide dismutase from extremophile Acidithiobacillus ferrooxidans

The gene sod in Acidithiobacillusferrooxidans may play a crucial role in its tolerance to the extremely acidic, toxic and oxidative environment of bioleaching. For insight into the anti-toxic mechanism of the bacteria, a three-dimensional （3D） molecular structure of the protein encoded by this gene was built by homology modeling techniques, refined by molecular dynamics simulations, assessed by PROFILE-3D and PROSTAT programs and its key residues were further detected by evolutionary trace analysis. Through these procedures, some trace residues were identified and spatially clustered. Among them, the residues of Asn38, Glyl03 and Glul61 are randomly scattered throughout the mapped structure; interestingly, the other residues are all distinctly clustered in a subgroup near Fe atom. From these results, this gene can be confirmed at 3D level to encode the Fe-depending superoxide dismutase and subsequently play an anti-toxic role. Furthermore, the detected key residues around Fe binding site can be conjectured to be directly responsible for Fe binding and catalytic function.

Effect of cadmium on the defense response of Pacific oyster Crassostrea gigas to Listonella anguillarum challenge

Heavy metal pollution can affect the immune capability of organisms. We evaluated the effect of cadmium （Cd） on the defense responses of the Pacific oyster Crassostrea gigas to Listonella anguillarum challenge. The activities of several important defensive enzymes, including superoxide dismutase （SOD）, glutathione peroxidase （GPx）, acid phosphatase （ACP）, Na＋, K＋-ATPase in gills and hepatopancreas, and phenoloxidase-like （POL） enzyme in hemolymph were assayed. In addition, the expression levels of several genes, including heat shock protein 90 （IrtSP9~））, metallothionein （MT）, and bactericidal/permeability increasing （BPI） protein were quantified by fluorescent quantitative PCR. The enzyme activities of SOD, ACP, POL, and GPx in hepatopancreas, and the expression of HSP90 were down-regulated, whereas GPx activity in the gill, Na＋, K＋-ATPase activities in both tissues, and MT expression was increased in Cd- exposed oysters post L. anguillarum challenge. However, BPI expression was not significantly altered by co-stress of L. anguillarum infection and cadmium exposure. Our results suggest that cadmium exposure alters the oysters＇ immune responses and energy metabolism following vibrio infection.