血定安对重症非控制性失血性休克再灌注期脂质过氧化反应的影响

目的 :研究血定安 (gelofusion)对重症非控制性失血性休克低压复苏期间脂质过氧化反应的影响。方法 :12只犬随机等分为平衡盐液 (LR)组 (组Ⅰ )和血定安 (GF)组 (组Ⅱ )。采用非控制性失血性休克模型 ,当MAP降到 2 0mmHg时 ,两组分别输注LR或GF并调节输液速度使MAP维持在 35～ 40mmHg。于放血前 (T1)、休克至MAP 40mmHg (T2 )、2 0mmHg (T3 )及复苏后 30min (T4 )、6 0min (T5)、12 0min (T6)时测血SOD和MDA ,记录HR、MAP、CO、CI,复苏 12 0min时计腹腔失血量。结果 :组Ⅰ输液量及腹腔失血量均显著大于组Ⅱ (P <0 .0 1,和P <0 .0 5 )。再灌注后组Ⅰ血SDO活性进行性下降 ,血MDA迅速上升 ,于T5时显著高于组Ⅱ ,而组Ⅱ再灌注期MDA与缺血期 (T3 )比较差异无显著性 ,且SOD呈上升趋势 ,其中T6SOD值显著高于组Ⅰ (P <0 .0 5 )。再灌注期间组ⅡMAP较组Ⅰ稳定。 12 0min组Ⅰ存活率低于组Ⅱ (P <0 .0 5 )。结论 :与LR比较 ,GF低压复苏重症非控制性失血性休克能显著降低再灌注期脂质过氧化反应程度 ,维持较稳定的血流动力学 ,降低动物死亡率。

Lipid peroxidation and antioxidant status in colorectal cancer

AIM: Reactive oxygen species (ROS) can induce carcinogenesis via DNA injury. Both enzymatic and non-enzymatic parameters participate in cell protection against harmful influence of oxidative stress. The aim of the present study was to assess the levels of final lipid peroxidation products like malondialdehyde (MDA) and 4-hydroxy-2-nonenal (4-HNE) in primary colorectal cancer. Moreover, we analysed the activity of main antioxidative enzymes, superoxide dismutase (Cu, Zn-SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GSSRG-R) and the level of non-enzymatic antioxidants (glutathione, vitamins C and E). METHODS: Investigations were conducted in 81 primary colorectal cancers. As a control, the same amount of sample was collected from macroscopically unchanged colon regions of the most distant location to the cancer. Homogenisation of specimens provided 10% homogenates for our evaluations. Activity of antioxidant enzymes and level of glutathione were determined by spectrophotometry. HPLC revealed levels of vitamins C and E and served as a method to detect terminal products of lipid peroxidation in colorectal cancer. RESULTS: Our studies demonstrated a statistically significant increase in the level of lipid peroxidation products (MDA-Adc. muc.-2.65±0.48 nmol/g, Adc.G3-2.15±0.44 nmol/g, clinical IV stage 4.04±0.47 nmol/g, P<0.001 and 4-HNE-Adc.muc. -0.44±0.07 nmol/g, Adc.G3-0.44±0.10 nmol/g, clinical IV stage 0.52±0.11 nmol/g, P<0.001) as well as increase of Cu,Zn-SOD (Adc.muc.-363±72 U/g, Adc.G3-318?8 U/g, clinical IV stage 421±58 U/g, P<0.001), GSH-Px (Adc.muc. -2143±623 U/g, Adc.G3-2005±591 U/g, clinical IV stage 2467±368 U/g, P<0.001) and GSSG-R (Adc.muc.-880±194 U/g, Adc.G3-795±228 U/g, dinical IV stage 951±243 U/g, P<0.001) in primary tumour comparison with normal colon (MDA-1.39±0.15 nmol/g, HNE-0.29±0.03 nmol/g, Cu, Zn-SOD-117±25 U/g, GSH-Px-1723±189 U/g, GSSG-R-625±112 U/g) especially in mucinous and G3-grade adenocarcinomas as well as clinical IV stage of colorectal cancer. We also observed a decrease of CAT activity (Adc.muc. -40±14 U/g, clinical IV stage 33±18 U/g vs 84±17 U/g, P<0.001) as well as a decreased level of reduced glutathione (clinical IV stage 150±48 nmol/g vs 167±15 nmol/g, P<0.05) and vitamins C and E (vit. C-clinical IV stage 325±92 nmol/g vs 513?4 nmol/g, P<0.001; vit. E-clinical IV stage 13.3±10.3 nmol/g vs 37.5±5.2 nmol/g). CONCLUSION: Colorectal carcinogenesis is associated with serious oxidative stress and confirms that gradual advancement of oxidative-antioxidative disorders is followed by progression of colorectal cancer.

Anti-lipid peroxidation and protection of liver mitochondria against injuries by picroside Ⅱ

AIM: To investigate the anti-lipid peroxidation and protection of liver mitochondria against injuries in mice with liver damage by picroside Ⅱ. METHODS: Three animal models of liver damage induced by carbon tetrachloride (CCl4: 0.1 mL/10 g, ip), D-galactasamine (D-GaIN: 500 mg/kg, ip) and acetaminophen (AP: 0.15 g/kg, ip) were respectively treated with various concentrations of picroside Ⅱ (5, 10, 20 mg/kg, ig). Then we chose the continuously monitoring method (recommended by International Clinical Chemistry League) to analyze serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) values, Marland method to detect the activity of manganese-superoxide dismutase (SOD) in liver mitochondria, TBA colorimetry to determine the content of malonicdialdehyde (MDA) in liver tissue, DTNB method to evaluate the activity of glutathioneperoxidase (GSH-Px) and Lowry method to detect protein level in liver tissue. Meanwhile, effects of picroside Ⅱ on the activity of ATPase and swelling extent of mitochondria in hepatocytes damaged by AP were also evaluated. RESULTS: Picroside Ⅱ could significantly prevent liver toxicity in the three models of liver damage. It decreased the high levels of ALT and AST in serum induced by the administration of CCl4, D-GaIN and AP, reduced the cellular damage of liver markedly, and appeared to be even more potent than the positive control drug of biphenyl dimethyl dicarboxylate pilules (DDB). In groups treated with different doses of picroside Ⅱ, compared to the model group, the content of MDA in serum decreased evidently, whereas the content of SOD and GSH-Px increased in a dose dependent manner, and the difference was statistically significant. Further, in the study of AP model, picroside Ⅱ inhibited AP-induced liver toxicity in mice, enhanced the activity of ATPase, improved the swelling extent of mitochondria and helped to maintain a normal balance of energy metabolism. CONCLUSION: Picroside II can evidently relieve hepatocyte injuries induced by CCI4, D-GaIN and AP, help scavenge free radicals, protect normal constructions of mitochondria membrane and enhance the activity of ATPase in mitochondria, thereby modulating the balance of liver energy metabolism, which might be part of the mechanisms of hepatoprotective effects of picroside Ⅱ.

Protective effects of ischemic preconditioning and application of lipoic acid prior to 90 min of hepatic ischemia in a rat model

AIM： To compare different preconditioning strategies to protect the liver from ischemia/reperfusion injury focusing on the expression of pro- and anti-apoptotic proteins. Interventions comprised different modes of ischemic preconditioning （IP） as well as pharmacologic pretreatment by α-lipoic acid （LA）. METHODS： Several groups of rats were compared： sham operated animals, non-pretreated animals （nt）, animals receiving IP （10 rain of ischemia by clamping of the portal triad and 10 min of reperfusion） prior to sustained ischemia, animals receiving selective ischemic preconditioning （IPsel, 10 min of ischemia by selective clamping of the ischemic lobe and 10 rain of reperfusion） prior to sustained ichemia, and animals receiving 500 1μmol α-LA injected i.v. 15 min prior to the induction of 90 min of selective ischemia. RESULTS： Cellular damage was decreased only in the LA group. TUNEL-positive hepatocytes as well as necrotic hepatocyte injury were also decreased only by LA（19 ± 2 vs 10 ± 1, P〈 0.05 and 29 ± 5 vs 12 ± 1, P 〈 0.05）. Whereas caspase 3- activities in liver tissue were unchanged, caspase 9- activity in liver tissue was decreased only by LA pretreatment （3.1 ± 0.3 vs 1.8 ± 0.2, P 〈 0.05）. Survival rate as the endpoint of liver function was increased after IP and LA pretreatment but not after IPsel. Levels of lipid peroxidation （LPO） in liver tissue were decreased in the IP as well as in the LA group compared to the nt group. Determination of pro- and anti-apoptotic proteins showed a shift towards anti-apoptotic proteins by LA. In contrast, both our IP strategies failed to influence apototic cell death. CONCLUSION： IP, consisting of 10 min of ischemia and 10 min of reperfusion, ischemia/reperfusion injury protects only partly against of the liver prior to 90 min of selective ischemia. IPsel did not influence ischemic tolerance of the liver. LA improved tolerance to ischemia, possibly by downregulation of pro-apoptotic Bax.

Role of oxygen free radicals in patients with acute pancreatitis

AIM:The generation of oxygen free radicals has been implicated in the pathogenesis of experimental pancreatitis. The aim of this study was to determine the role of oxygen free radicals in patients with acute pancreatitis. METHODS:The plasma levels of C-reactive protein(CRP), lipid peroxide(LPO),myeloperoxidase(MPO)and superoxide dismutase(SOD)were measured in 13 patients with acute pancreatitis and 14 healthy volunteers. RESULTS:Among the patients with acute pancreatitis,there were higher plasma levels of LPO and MPO and lower SOD activity in patients with severe pancreatitis than in those with mild pancreatitis.However,there was no significant difference in the serum marker of oxidative stress no matter what the etiology was.The LPO level was especially correlated with the concentration of serum CRP and CT severity index. CONCLUSION:The oxygen free radicals may be closely associated with inflammatory process and the severity of acute pancreatitis.Especially,the concentration of plasma LPO is a meaningful index for determining the severity of the disease.

Moro orange juice prevents fatty liver in mice

AIM:To establish if the juice of Moro,an anthocyaninrich orange,may improve liver damage in mice with diet-induced obesity.METHODS:Eight-week-old mice were fed a high-fat diet(HFD) and were administrated water or Moro juice for 12 wk.Liver morphology,gene expression of lipid transcription factors,and metabolic enzymes were assessed.RESULTS:Mice fed HFD displayed increased body weight,insulin resistance and dyslipidemia.Moro juice administration limited body weight gain,enhanced insulin sensitivity,and decreased serum triglycerides and total cholesterol.Mice fed HFD showed liver steatosis associated with ballooning.Dietary Moro juice markedly improved liver steatosis by inducing the expression of peroxisome proliferator-activated receptor-α and its target gene acylCoA-oxidase,a key enzyme of lipid oxidation.Consistently,Moro juice consumption suppressed the expression of liver X receptor-α and its target gene fatty acid synthase,and restored liver glycerol-3-phosphate acyltransferase 1 activity.CONCLUSION:Moro juice counteracts liver steatogenesis in mice with diet-induced obesity and thus may represent a promising dietary option for the prevention of fatty liver.

Enzyme responses and lipid peroxidation in gills and hepatopancreas of clam Mactra vereformis, following cadmium exposure

To assess the toxicity of heavy metal pollution to marine intertidal shellfish, enzymatic responses and lipid peroxidation were investigated in the clam Mactra vereformis exposed to cadmium under laboratory conditions. Three antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase, GPx), two immune defense enzymes (acid phosphatase, ACP; alkaline phosphatase, ALP), and one lipid peroxidation product (malondialdehyde, MDA) were measured in the gills and the hepatopancreas of the clam exposed to 0, 25, 75, and 125 μg/L cadmium for 0, 1, 3, 5, and 7 d. The results show that the concentrations of antioxidant enzymes in the organs soared to a peak value on the first day and then decreased afterwards in most cases. CAT and GPx activities in the hepatopancreas were higher than in the gills, but the SOD activity was lower in the hepatopancreas. ACP activity was unchanged until Day 3 in the hepatopancreas and until Day 5 in gills, when it began to increase. ALP activity showed no significant relationship with Cd treatment. MDA concentrations increased in the two tissues after Cd exposure, peaked on Day 3 in gills, and on Day 5 in hepatopancreas. These observations show that changes in the activities of antioxidant enzymes and ACP reflect the time course of oxidative stress in the clam caused by Cd, and could be used as potential biomarkers for ecotoxicological bioassays of heavy metals.

Nitroglycerine effects on portal vein mechanics and oxidative stress in portal hypertension

AIM:Тo examine the effects of nitroglycerine on portal vein haemodynamics and oxidative stress in patients with portal hypertension.METHODS:Thirty healthy controls and 39 patients with clinically verified portal hypertension and increasedvascular resistance participated in the study.Liver di-ameters,portal diameters and portal flow velocities were recorded using color flow imaging/pulsed Doppler detection.Cross-section area,portal flow and index of vascular resistance were calculated.In collected blood samples,superoxide anion radical (O 2-),hydrogen per-oxide (H 2 O 2),index of lipid peroxidation (measured as TBARS) and nitric oxide (NO) as a marker of endothelial response (measured as nitrite-NO 2-) were determined.Time-dependent analysis was performed at basal state and in 10th and 15th min after nitroglycerine (sublingual 0.5 mg) administration.RESULTS:Oxidative stress parameters changed sig-nificantly during the study.H 2 O 2 decreased at the end of study,probably via O 2-mediated disassembling in Haber Weiss and Fenton reaction;O 2-increased signifi-cantly probably due to increased diameter and tension and decreased shear rate level.Consequently O 2-and H 2 O 2 degradation products,like hydroxyl radical,initi-ated lipid peroxidation.Increased blood flow was to some extent lower in patients than in controls due to double paradoxes,flow velocity decreased,shear rate decreased significantly indicating non Newtonian char-acteristics of portal blood flow.CONCLUSION:This pilot study could be a starting point for further investigation and possible implemen-tation of some antioxidants in the treatment of portal hypertension.

Effect of Different Sources of Dietary Fibre on Oxidative Stress in Laboratory Rats

The objective of the present study was to determine the effect of different sources of dietary fibre on the oxidative stress induced by a high fat diet in laboratory rats. Thirty two laboratory rats were penned individually and divided into four groups： CONT （high fat diet）, G （70 g guar gum/kg）, P （70 g apple pectin/kg） and WB （155 g wheat bran/kg）. After 11 or 13 days of treatment DNA damage of blood leukocytes was measured by Comet assay and lipid peroxidation was studied by determining the malondialdehyde （MDA） concentration in liver and in urine. In comparison with group CONT, the degree of DNA damage was significantly lower in group WB. In groups G and P DNA damage was also reduced but not significantly. Similar results were also obtained for the liver MDA concentration. All three studied groups showed reduced liver MDA concentrations but only group WB was significant compared to group CONT. In comparison with group CONT, the groups WB and P had significantly reduced 24-hour urine MDA excretion, hut not group G. The results of the experiment confirmed that wheat bran intake effectively reduces oxidative stress induced by a high fat diet.

The Content of Selenium and Other Ten Chemical Elements in Boletus Edulis from Bulgaria and Inhibition of Lipid Peroxidation

The goal of this study was to determine the content of such biological active metals as Se, Hg, AI, Cu, Zn, As, Cd, Pb, Mg, Ca and Fe in Boletus Edulis mushrooms and to study the effect of mushrooms as inhibitors of blood serum copper-initiated lipid peroxidation. The metals content was determined by ICP-OES technique and blood lipids peroxidation in vitro was assessed by thiobarbituric acid-reactive substances measurement. The dependency between quality and content of the determined biological active metals has been traced. Samples were analyzed of wild growing mushrooms Boletus Edulis from two mountain regions in Bulgaria. On the average the content of Se in Boletus Edulis was found to be 25 mg/kg dried mushroom, this content being higher in tubules than in fleshy part. We found that Boletus Edulis mushrooms inhibited lipid peroxidation in the concentration dependent manner. The effective concentration of Boletus Edulis is in 5 times lower compared to the concentration of Cantharellus Cibarius resulting in similar lipid peroxidation inhibition. This effect can be explained by 56 times higher content of Se and by 1.5 and 3 times lower content of such initiators of lipid peroxidation as Cu and Fe in Boletus Edulis compared to Cantharellus Cibarius. A system with a source of infrared radiation heating, developed by authors, was used for the mushroom mineralization. We conclude that Boletus Edulis is an effective inhibitor of blood lipid peroxidation and in 5 times stronger rather than Cantharellus Cibarius.

Effects of Waterborne Cu and Cd on Anti-oxidative Response, Lipid Peroxidation and Heavy Metals Accumulation in Abalone Haliotis discus hannai Ino

The aim of this study was to compare the effects of waterbome copper （Cu） and cadmium （Cd） on survival, anti-oxida- tive response, lipid peroxidation and metal accumulation in abalone Haliotis discus hannai. Experimental animals （initial weight： 7.49 g±0.01 g） were exposed to graded concentrations of waterborne Cu （0.02, 0.04, 0.06, 0.08 mg L-1） or Cd （0.025, 0.05, 0.25, 0.5 mgL-1） for 28 days, respectively. Activities of the anti-oxidative enzymes （catalase, CAT; superoxide dismutase, SOD; glutathione peroxidases, GPx; glutathione S-transferase, GST）, contents of the reduced glutathione （GSH） and malondiadehyde （MDA） in the hepatopancreas, and metal accumulation in hepatopancreas and muscles were analyzed after 0, 1, 3, 6, 10, 15, 21, 28 days of metal exposure, respectively. Results showed that 0.04 mg L-1, 0.06 mg L-1 and 0.08 mgL-1 Cu caused 100% death of abalone on the 21st, 10th and 6th day, respectively. However, no dead abalone was found during the 28-day waterborne Cd exposure at all experimental concentrations. Generally, activities of SOD and GST in hepatopancreas under all Cu concentrations followed a decrease trend as the exposure time prolonged. However, these activities were firstly increased and then decreased to the control level and increased again during Cd exposure. Activities of CAT in all Cu exposure treatments were higher than those in the control. These activities were firstly increased and then decreased to the control level and increased again during Cd exposure. Contents of MDA in hepatopancreas in all Cu treatments significantly increased first and then decreased to the control level. However, the MDA contents in hepatopan- creas were not significantly changed during the 28-day Cd exposure. The metals accumulation in both hepatopancreas and muscles of abalone significantly increased with the increase of waterborne metals concentration and exposure time. These results indicated that H. discus hannai has a positive anti-oxidative defense against Cu or Cd. In conclusion, anti-oxidative mechanism in abalone to resist waterborne Cu did not follow the same pattern as that for waterborne Cd.

Effect of Microwave Radiation on Dielectric Behavior of Two Vegetable Oils

The effect of microwave （MW） heating on the dielectric properties and oxidation processes of virgin olive oil and refined sunflower oil were determined by dielectric and UV- spectroscopy. Samples were heated in the microwave oven （850 W, 2.450 MHz） for 0 to 14 minutes. The results show degradation of dielectric characteristics, conductivity and oxidative stability of investigated oils, increasing with the exposure time. UV spectrum shows only one defined peak at 206 nm for olive oil confirming the dominant presence of monounsaturated fats and four peaks for sunflower oil （203 nm, 230 nm, 269 nm and 278 nm） dependent on polyunsaturated acid fats contents. Increasing of absorbance at all peak wave lengths indicates production of lipid oxidation, due to formation of conjugated monoenes and dienes and in small amounts due to trienes and secondary products like ketoaldehydes. Dielectric constant for olive oil is stable and almost unchangeable with MW radiation while sunflower oil＇s c＇ oscillates around the origin value in greater rate. Dielectric loss e＂ decreases with increasing time of MW radiation and its maximum shifts towards higher frequencies for sunflower oil indicating shortening of the relaxation times, while for olive oil it is unchanged. Cole-Cole analysis show the presence of only one relaxation process in the oils. Conductivity of oils is increasing in similar way with increasing frequency following the Jonscher＇s power law and is not changed with MW exposure time. Olive oil has conductivity higher for four orders of magnitude than sunflower oil, which is connected to the high content of monounsaturated fats. The differences between sunflower and olive oil characteristics are discussed.

Acute Toxicity of Cadmium on the Antioxidant Defense Systems and Lipid Peroxidation in the Juveniles of Genetically Improved Farmed （GIFT） Tilapia Oreochromis Niloticus

Heavy metals pose a potential threat to aquatic organisms. In this study, a static-renewal acute toxicity test was conducted to investigate the effects of cadmium on the antioxidant defense systems （both enzymatic and non-enzymatic） and lipid peroxidaton in liver and gill tissues of juvenile GIFT tilapia Oreochromis niloticus. After 8 days of exposure to Cd （0, 0.016, 0.08, 0.4 and 2 mg/L）, livers accumulated significantly more Cd than gills. Catalase （CAT）, superoxide dismutase （SOD） and glutathione S-transferase （GST） activities were stimulated only at the highest concentration tested （2 mg/L）. Glutathione peroxidase （GPx） activity was stimulated in the gill while inhibited in the liver, these alternations in gill and liver showed a strong relationship with Cd levels in these tissues. This may indicate either a tissue-specific response of GPx to Cd or, most probably, a hormetic effect of Cd on GPx. Cd increased GSH levels and decreased the ratio GSSG/GSH in fish livers at 2 mg/L. Cd exposure resulted in an elevated level of MDA in the livers of fish at 2 mg/L, indicating that Cd caused lipid peroxidation. Taken together, the results demonstrated that Cd altered the enzymatic and non-enzymatic defensive systems and caused lipid peroxidation in O. niloticus at relatively high concentrations （compared to environmentally relevant concentrations）. In addition, the results implied that O. niloticus could tolerate high level of Cd in sites polluted by Cd.

Changes of free iron contents and its correlation with lipid peroxidation after experimental spinal cord injury

Objective: To observe the dynamic changes of fre e iron contents and its relationship to the changes of lipid peroxidation after experimental spinal cord injury (SCI). Methods: Sprague Dawley rats were randomly divided into three g roups: Group A (n=6) received no operation; Group B (n=48) received only laminec tomy (sham); and Group C (n=48) received both laminectomy and traumatic injury ( SCI model). The SCI animal models were made by using an modified Allens weight -drop device (50 g.cm) on T_ 12 . Rats were sacrificed at 0.5 ,1,3,6,12,24 hours after injury. The levels of free iron involved in spinal cord segm ents at different time points were measured by bleomycin assay. The malondialdeh yde (MDA) was also measured by the thiobarbituric acid (TBA). Results: After SCI in Group C,the level of free iron showed a significant increase at 0.5 hour compared to Groups B and A,restored to th e control level at 6 h; the level of MDA was increased at 0.5 hour,peaked a t 3 hours,returned to the control level at 12 hours; the concentrations of free iron and lipid peroxidation in injured rats were significantly and positively c orrelated at 0.5 -3 hours. Conclusions: After SCI the levels of free iron are increased qu ickly and might be a major contributor to lipid peroxidation in injured spinal c ord.