室内醇酸色漆挥发物对小鼠多器官超氧化物化歧酶的抑制作用

目的观察室内醇酸色漆挥发物对小鼠多器官超氧化物歧化酶的抑制作用。方法将30只ICR小鼠分为3 h急性染毒组、30 h染毒组和对照组,每组10只;以醇酸色漆为受试物应用静式吸入染毒方法,染毒期间及恢复期观察其行为变化,染毒后测定其心脏、肺脏、肝脏、肾脏中超氧化物歧化酶(SOD)的水平。结果3 h急性染毒组,小鼠吸入醇酸色漆挥发物对心、肾组织SOD酶活力影响与对照组比较,差异无统计学意义(P>0.05);肺、肝组织SOD酶活力分别为(74.89±34.29)、(84.31±18.53) U/mg pro,与对照组比较明显降低,差异有统计学意义(P<0.01)。30 h染毒组,小鼠吸入醇酸色漆挥发物其心、肺、肝组织SOD酶活力(32.5±15.64)、(35.47±17.43)、(68.15±12.92)U/mg pro,与对照组比较明显下降,差异有统计学意义(P<0.01);肾组织SOD酶活力的变化不明显,与对照组比较,差异无统计学意义(P>0.05)。结论醇酸色漆挥发物可对小鼠多器官SOD产生抑制作用,具有一定的毒性作用。

Growing Development and Physiological Characteristics of Seeds Harvested Different Days after Pollination and Their 7-day Seedlings of Two Yellow-Seeded Cultivars of Brassica napus L.

This study aimed to understand the growing development and physiological characteristics of seeds harvested different days after pollination and the seedlings emerged from the seeds of yellow-seeded Brassica napus L..Two yellow-seeded cultivars‘Hongyuan 558’and‘Qinyou 806’were selected in this study,and 50 seeds were collected 30,35,and 40 d after pollination,respectively.The seeds were weighed and placed on filter paper for hydroponic experiments.The seed germination rate was determined 3-5 d later.The physiological indicators including superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT)activities and malondialdehyde(MDA)content were measured for the seeds harvested different days after pollination and the 7-day-seedlings emerged from the seeds.The results showed that the seed dry weights and germination rates of both‘Qinyou 806’and‘Hongyuan 558’increased as the days after pollination increased,especially 30-35 d after pollination.The germination rate and dry and fresh weights of the seeds showed no significant differences between the two cultivars,and almost all the seeds germinated 40 d after pollination.As the days after pollination increased,the SOD activities in the seeds of both cultivars first increased and then decreased,reaching their peaks 35 d after pollination,which may be related to encountering adverse stress.The POD activity in the seeds of‘Qinyou 806’kept declining,and that of‘Hongyuan 558’first increased and then decreased,which may be related to the antioxidant mechanism and adaptive regulation.The CAT activities in the seeds of both cultivars first decreased and then increased.The MDA content in the seeds of‘Qinyou 806’first decreased and then increased,while that of‘Hongyuan 558’kept reducing and was the highest in the seeds 30 d after pollination,which indicated‘Hongyuan 558’was mildly affected by the environment and had strong resistance.The activities of SOD and POD in the seedlings of two cultivars that were emerged from the seeds 35-40 d after pollination became weakened,which may be related to their exposure to stress.The CAT activity in the seedlings of‘Hongyuan 558’was generally higher than that of‘Qinyou 806’,indicating that‘Hongyuan 558’had stronger stress resistance.The MDA content in the seedlings emerged from the seeds 35-40 d after pollination showed a decreasing trend,indicating that the seedlings emerged from the seeds harvested at this stage had mild cell membrane damage and enhanced stress resistance.In conclusion,‘Hongyuan 558’had strong environmental adaptability and stress resistance.

Analysis on Activity of Immunity-related Enzymes in First Familiar Generation and Self Cross F1 of Platichthys stellatus Pallas

[Objective] The aim was to study the activity of immunity-related enzymes in each tissue of self cross F1 of Platichthys stellatus Pallas and first familiar generation of P.stellatus ♀×Verasper variegates ♂.[Method] The activity difference of three important non-specific immunity-related enzymes：acid phosphatase （ACP）,alkaline phosphatase （AKP） and superoxide dismutase （SOD） existed in muscle,liver,spleen and intestine of first familiar generation and self cross F1 of P.stellatus was compared.[Result] The activity of ACP and AKP in muscle,liver and intestine of first familiar generation was higher than that of self cross F1,while the activity of ACP and AKP in liver of first familiar generation showed no significant difference with that of self cross F1; the SOD activity decreased significantly in tissues expected for muscle.[Conclusion] The result had provided theoretic basis for the breeding of P.stellatus.

Physiological characteristics changes of Aesculus chinensis seeds during natural dehydration

A study was conducted to determine the physiological characteristics changes of Aesculus chinensis seeds during natural dehydration in 2003. The results showed that A. chinensis seeds were recalcitrant with being highly desiccation-sensitive. The seed moisture content of fresh fruits was higher than 60%. When the seeds were naturally dried for 30 days, their moisture content declined to 30.2% and their viability was completely lost. The seed germination percentage had a small increase at the beginning of desiccation and then decreased rapidly. The relative electrical conductivity of the A. chinensis seeds increased along with a decrease in seed moisture content. However, there was an abnormal increase in relative electrical conductivity when the seed moisture content was between 53.7% and 50.9%. Superoxide dismutase （SOD） activity decreased rapidly in the period of desiccation except for an abnormality when the seed moisture content was between 53.7% and 50.9%. Malondialdehyde （MDA） content increased slowly at the early stage of desiccation and then rose rapidly after the moisture content was below 50.9%. The soluble sugar content in seeds slowly increased with the increasing period of desiccation. The seed germination percentage was at the high level when seed moisture content was in range of 47%- 60%, which suggests that this was the optimum moisture content for maintaining A. chinensis seed viability.

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.

Effect of Polyamine Priming on Chilling Tolerance of Lolium perenne during Seed Imbibition

[Objective] This study aimed to investigate the effect of potyamine priming on physiological and biochemical variations of Lolium perenne embryos and seed germination. [Method] With annual Lolium perenne （Diamond T and Grazing-8000） as experimental materials, after priming with 0.5 mmol/L putrescine （Put）, spermidine （Spd） and spermine （Spm） for 24 h and chilling imbibition at 5 ℃ for 12, 24, 36 and 48 h, the effect of Put, Spd and Spm priming on chilling tolerance and germination ability of annual Lolium perenne seeds during imbibition was investigated. [Result] Put, Spd and Spm priming improved the activities of peroxidase （POD）, catalase （CAT）, superoxide dismutase （SOD） and ascorbate peroxidase （APX） and content of soluble protein content under low temperature stress, significantly in-creased the germination rate, and shortened the average germination duration. After chilling imbibition for 48 h, compared with the control, the average germination rate of annual Lolium perenne seeds was improved by 15.5% and 12.0% after Put, Spd and Spm priming, and the average germination duration was shortened by 1.21 and 1.14 d. During seed imbibition, the chilling tolerance of Grazing-8000 was stronger than that of Diamond T. Overall, Put, Spd and Spm treatment could increase the chilling tolerance of annual Lolium perenne seeds during imbibition, and improve the germination ability of seeds under low temperature stress. [Conclusion] Results of this study provided theoretical basis for the application of seed priming technology in the production of annual ryegrass.

Physiological Changes during the Process of Pericarp Browning in the Postharvest Litchi

[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determined in order to identify the underlying mechanisms. [Method] Matured Feizixiao fruits were stored at 25 ℃ and 70%±5% relative humidity. The physiological changes happened in pericarp during storage were tested at an 8-hour interval. [Result] The fruit of Feizixiao (Litchi chinensis Sonn. cv Feizixiao) turned completely brown within 72 h after being harvested under the experimental conditions. Sharp increase of the browning index occurred from 48 to 64 hours after harvest (HAH). With the browning of pericarp,water content of the whole fruit and pericarp decreased continuingly. In contrast,there were no significant changes in the water content of pulp during the same period. MDA content,pH value and relative leakage rate of pericarp were increased during storage. Most of pigment contents including anthocyanin,flavonoid,phenols,chlorophyll a and total chlorophyll decreased. POD activity was initially increased in 32 HAH and then decreased afterwards. PPO activity was decreased continuously,while the activities of catalase and superoxide dismutase exhibited the pattern of 'increasing-decreasing-increasing' as the storage time progressed. Correlation,stepwise regression and path analyses showed that water loss of pericarp was the major factor of pericarp browning. Principal and cluster analyses showed that there were two stages of pericarp browning during the course of litchi storage. [Conclusion] Water status of pericarp was the most important factor affecting pericarp browning. The pericarp browning happened by stages,which was mainly determined by the water loss of pericarp.

6 Kinds of Isozymes after Long-term Subculture of Emmenopterys henryi Oliv.

[Objective] The aim was to study the changes of zymography in 6 kinds of isozymes after long-term subculture of Emmenopterys henryi Oliv.. [Method] Non-denaturing polyacrylamide gel electrophoresis was used to analyze isozyme patterns such as esterase (EST),acid phosphatase (ACP),ATP enzyme (ATPase),amylase (AMY),superoxide dismutase (SOD) and peroxidase (POD) in long-term subculture callus of Emmenopterys henryi Oliv. [Result] The research showed that there were differences among the 6 kinds of isozymes in embryogenic callus and non-embryogenic callus of Emmenopterys henryi Oliv.,and both levels could be taken as the basis for identification,the EST,ACP,and POD of non-embryogenic callus were significantly higher than embryogenic callus. The browning of non-embryogenic callus was non-level in the AMY,SOD and POD isozymes when was compared with normal non-embryogenic callus,while the EST,ACP and ATPase isozymes decreased; When the browning of embryogenic callus was contrasted with normal embryogenic callus,EST isozyme increased and the other 5 kinds of enzymes decreased. [Conclusion] The study provided theoretical basis for research morphological difference and browning of long-term tissue culture of Emmenopterys henryi Oliv..

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...

Response of SOD Activity of Earthworm to Soil Plumbum Pollution

The response of the superoxide dismutase （SOD） activities of earthworm （Eisenia fetida） to soil plumbum （Pb） pol ution was studied in the artificial soil test. The results indicated that the SOD activity in earthworm exposed to low-concentra-tion Pb declined on the 5th day of acute toxicity test, while that exposed to high-concentration Pb increased by different extents. On the 15th day, the SOD activity increased slightly along with soil Pb concentration increasing.

Study on the Mechanism of Innovative Montmorillonite for Diarrhea Treatment

[Objective] This study aimed to investigate the mechanism of innovative montmorillonite for diarrhea treatment. [Method] Thirty healthy weanling piglets （Duroc x Landrace x Yorkshire） were randomly divided into five groups and fed with basal diet, basal diet ＋ 1 g/kg innovative montmorillonite, basal diet ＋ 3 g/kg innovative montmorillonite, basal diet ＋ 5 g/kg innovative montmorillonite and basal diet ＋ 3 g/kg Bacillus subtilis microecologic agent, respectively. After four weeks, blood samples were collected via precaval vein, to detect the content of TFF3, NO and SOD in serum by ELISA kits. [Result] Compared with blank control group, the content of TFF3, NO and SOD in high-dose innovative montmorillonite group was extremely significantly increased, extremely significantly reduced and significantly in- creased, respectively; the content of TFF3 and NO in middle-dose innovative mont- morillonite group was significantly increased and significantly reduced, respectively. [Conclusion] Innovative montmorillonite may exert beneficial therapeutic actions on diarrhea by increasing TFF3 and SOD levels and decreasing NO level.

Effects of Breviscapine on the Changes in Antioxidant Enzyme Activity Induced by Cerebral Ischemia-reperfusion in Rats

\ Effects of breviscapine, the active ingredient isolated from Erigeron breviscapus (Vant) Handmazz, on the changes in antioxidant enzyme activity induced by cerebral ischemiareperfusion in rats were explored. It was found that breviscapine improved the activities of superoxide dismutase (SOD), GSHperoxidase and catalase, while decreasing the malondialdehyde (MDA) content in the brain, which was benificial in reducing the damage from cerebral ischemiareperfusion.

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.

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.

Antioxidant activity of chito-oligosaccharides on pancreatic islet cells in streptozotocin-induced diabetes in rats

AIM:To investigate the antioxidant activity of chitooligosaccharides(COSs)on pancreatic islet cells in diabetic rats induced by streptozotocin. METHODS:The antioxidant effect of COSs on pancreatic islet cells was detected under optical microscopy and with colorimetric assay and gel electrophoresis.The activities of glutathione peroxidase and superoxide dismutase,total antioxidant capacity,and content of malondialdehyde in serum and tissue slices of pancreas were examined after 60 d to determine the effect of COSs in streptozotocin-induced diabetes in rats. RESULTS:COSs can prohibit the apoptosis of pancreatic islet cells.All concentrations of COSs can improve the capability of total antioxidant capacity and activity of superoxide dismutase and decrease the content of malondialdehyde drastically.Morphological investigation in the pancreas showed that COSs have resulted in the reduction of islets,loss of pancreatic cells,and nuclear pyknosis of pancreatic cells. CONCLUSION:COSs possess various biological activities and can be used in the treatment of diabetes mellitus.

Efficacy of intramuscular diclofenac and fluid replacement in prevention of post-ERCP pancreatitis

AIM： TO assess the efficacy of intramuscular diclofenac and fluid replacement for prevention of post-endoscopic retrograde cholangiopancreatography （ERCP） pancreatitis.METHODS： A prospective, placebo-controlled study was conducted in 80 patients who underwent ERCP. Patients were randomized to receive parenteral diclofenac at a loading dose of 75 mg followed by the infusion of 5-10 mL/kg per hour isotonic saline over 4 h after the procedure, or the infusion of 500 mL isotonic saline as placebo. Patients were evaluated clinically, and serum amylase levels were measured 4, 8 and 24 h after the procedure.RESULTS： The two groups were matched for age, sex, underlying disease, ERCP findings, and type of treatment. The overall incidence of pancreatitis was 7.5% in the diclofenac group and 17.5% in the placebo group （12.5% in total）. There were no significant differences in the incidence of pancreatitis and other variables between the two groups. In the subgroup analysis, the frequency of pancreatitis in the patients without sphincter of Oddi dysfunction （SOD） was significantly lower in the diclofenac group than in the control group （ρ = 0.047）.CONCLUSION： Intramuscular diclofenac and fluid replacement lowered the rate of pancreatitis in patients without SOD.

N-acetylcysteine attenuates alcohol-induced oxidative stess in rats

AIM:To investigate free-radical scavenger effect of n- acetylcysteine in rats intragastrically fed with ethanol. METHODS:Twenty-four rats divided into three groups were fed with ethanol (6 g/kg/day,Group 1),ethanol and n- acetylcysteine (1 g/kg,Group 2),or isocaloric dextrose (control group,Group 3) for 4 weeks.Then animals were sacrificed under ether anesthesia,and intracardiac blood and liver tissues were obtained.Measurements were made in both serum and homogenized liver tissues. Malondialdehyde (MDA) level was measured by TBARS method.Glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) levels were studied by commercial kits. Kruskal-Wallis test was used for statistical analysis. RESULTS:ALT and AST in Group 1 (154 U/L and 302 U/L, respectively) were higher than those in Group 2 (94 U/L and 155 U/L) and Group 3 (99 U/L and 168 U/L) (P=0.001 for both).Serum and tissue levels of MDA in Group 1 (1.84 nmol/mL and 96 nmol/100 mg-protein) were higher than that in Group 2 (0.91 nmol/mL and 64 nmol/100 mg protein) and Group 3 (0.94 nmol/ml and 49 nmol/100 mg-protein) (P<0.001 for both).On the other hand,serum GSH-Px level in Group 1 (8.21 U/g Hb) was lower than that in Group 2 (16 U/g Hb) and Group 3 (16 U/g-Hb) (P<0.001).Serum and liver tissue levels of SOD in Group 1 (11 U/mL and 26 U/100 rag-protein) were lower than that in Group 2 (18 U/ mL and 60 U/100 mg protein) and Group 3 (20 U/mL and 60 U/100 rag-protein) (P<0.001 for both). CONCLUSION:Ethanol-induced liver damage was associated with oxidative stress,and co-administration of n-acetylolsteine attenuates this damage effectively in rat model.

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.