Perioperative values of glutathione peroxidase activity and malondialdehyde levels in enolic cirrhotic recipients of a liver transplant

Reactive oxygen species play a central role in ischemia-reperfusion injury after organ transplantation. They are degraded by endogenous radical scavengers such as antioxidant enzymes. The purpose of this study was to evaluate the temporal variation in glutathione peroxidase (GPX) activity and malondialdehyde (MDA) levels among alcoholic cirrhotic recipients of liver transplantations. The study included 30 recipients: 26 males and 4 females in the provided blood samples before and after transplantation. The results showed significant enhancement of MDA levels at 1 and 6 hours after transplantation: 4.458 ± 2.273 μmol/L and 4.4628 ± 2.405 μmol/L respectively (P < .001). In contrast, GPX activity showed a maximum at 3 days there after 3.541 ± 2,315 nmol/mg protein. In conclusion, although MDA levels show an enormous increase at 1 hour after transplantation suggesting lipid peroxidation, they were compensated by GPX activity thereafter, indicating control of the oxidative stress generated by liver transplantation.     

The effect of dehydroepiandrosterone on renal ischemia-reperfusion-induced oxidative stress in rabbits

Reactive oxygen species (ROS) can play an important role in the pathogenesis of ischemia-reperfusion (I/R) injury. Dehydroepiandrosterone (DHEA) is one of the hormones secreted from adrenal glands, and in some studies it has been shown that DHEA has antioxidant properties. This experimental study was designed to determine the effect of DHEA on I/R-induced oxidative stress in rabbit kidney. Twenty-one rabbits were divided into three groups. Rabbits were subjected to 60 min of left renal pedicle occlusion followed by 24 h of reperfusion. DHEA (50 mg/kg) (I/R + DHEA group) or equal volume of vehicle (I/R group) was administered 3 h prior to ischemia. The control group received only laparotomy without I/R, DHEA or vehicle. At the end of the reperfusion periods, rabbits were decapitated. Renal tissues were taken for determination of malondialdehyde (MDA) levels as an indicator of lipid peroxidation and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities as antioxidant enzymes. In the I/R group, while renal SOD and CAT activities were significantly lower, MDA levels were significantly higher than in the I/R + DHEA group and controls. In the I/R + DHEA group, enzyme activities and MDA levels were similar to the controls. There was no significant difference in terms of renal GPX activity among the groups. DHEA may have a beneficial effect on renal tissue against oxidative damage due to I/R by preventing decreases in some antioxidant enzyme activities.     

Alteration in plasma antioxidant capacity in various degrees of chronic renal failure

AIM, PATIENTS AND METHODS: To obtain a more comprehensive profile of extracellular antioxidant capacity in chronic renal failure (CRF), markers of oxidative stress (malondialdehyde, MDA and hydrogen peroxide), protein SH groups (as an important chain-breaking antioxidant) and activity of antioxidant enzymes (glutathione peroxidase, [GPX], catalase and superoxide dismutase, [SOD]) were studied in plasma of 36 non-dialyzed patients with various degrees of CRF and 10 hemodialyzed (HD) patients. RESULTS: The results show that plasma MDA concentrations significantly increase with the severity of kidney dysfunction (r = -0.543, p < 0.01). A marked and profound fall in plasma thiol group levels was observed in all groups tested, independent of the degree of renal failure (r = 0.082, p > 0.05). Plasma SOD activity increased in CRF patients with the progression of renal insufficiency (r = -0.370, p < 0.05). On the other hand, plasma GPX activity decreased progressively in strong correlation with endogenous CCr (r = 0.712, p < 0.001). However, despite this imbalance between extracellular SOD and GPX activities, plasma concentration of hydrogen peroxide remained unchanged in non-dialyzed CRF patients. Catalase activity in non-dialyzed CRF patients was increased, suggesting the significant involvement of catalase in the regulation of plasma hydrogen peroxide level. CONCLUSION: In hemodialyzed patients significantly lower plasma catalase activity, associated with higher hydrogen peroxide levels, was found. It seems reasonable to assume that the imbalance in the activity of extracellular antioxidant enzymes in chronic renal failure may result in accumulation of free radical species, and in unscheduled oxidation of susceptible molecules.     

Evaluation of oxidative stress after repeated intravenous iron supplementation

Parenteral iron has been recommended for the treatment of iron deficiency in the majority of maintenance hemodialyzed (HD) patients. However, iron supplementation and consequent over saturation of transferrin and high iron levels, may aggravate oxidative stress already present in these patients. This study aimed to further clarify the role of repeated intravenous iron therapy as a supplementary cause of oxidative stress in HD patients. Markers of free radical activities (carbonyl reactive derivatives, CRD, thiol groups, SH, malondialdehyde, MDA) and antioxidant enzyme activities (superoxide dismutase, SOD and glutathione peroxidase, GPX) were determined in plasma and red blood cells (RBC) of 19 hemodialysis patients given a total iron dose of 625 mg (ferrogluconat, Ferrlecit, 62.5 mg). Blood samples were taken before the first and after the last dose of iron. Twenty apparently normal subjects served as healthy controls. Before iron treatment, HD patients exhibited increased concentrations of MDA and CRD in plasma and red blood cells, accompanied with impaired antioxidant capacity. All patients responded to iron therapy with a significant increase in their serum ferritin, serum iron, hemoglobin, and red blood cells levels. However, iron treatment resulted in enhanced oxidative stress in plasma of HD patients, since significant increase in plasma MDA and CRD concentrations, together with a decrease in nonprotein SH groups levels were detected. Supplementation with iron did not significantly influence plasma SOD and GPX activities, nor did any of the red blood cell parameters tested. Our data show that, despite improvement in hematological parameters, an increase in iron stores due to supplementation could also contribute to increased free radical production in HD patients.     

Red cell antioxidant enzymes and prognostic indexes in patients with burns

Red cell superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) were measured in 66 burned patients (57 men, 9 women, age 16–78 years). BSAB varied from 15 to 93% and ABSI from 3 to 14 points. In the first week after injury the activity of SOD was significantly decreased as compared with the activity of the enzymes in the control group and was also below the reference values. Later the activity of SOD increased up to the normal range. The activity of CAT followed a similar pattern but the differences were not significant. No significant changes in red cell GPX were found during the monitored period. We did not find any significant association between the antioxidant enzyme activities and the markers of burns severity. On the other side there was a significant indirect association between the change of SOD activity (calculated as a difference between the first week values after the injury and the activities measured later) and BSAB.     

Glutathione S-transferase-P1 expression correlates with increased antioxidant capacity in transitional cell carcinoma of the urinary bladder

OBJECTIVES: Our aim was to perform a comprehensive analysis of the antioxidant capacity of transitional cell carcinoma (TCC) of urinary bladder and discern the role of enzymes associated with glutathione (GSH) in maintaining high GSH levels in these tumours. Because the redox-sensitive protein glutathione S-transferase P1 (GSTP1) might provide an important link between high antioxidant capacity and inhibition of apoptotic pathways, we also explored how the redox state in tumour cells interacts with the expression of GSTP1. METHODS: We examined spectrophotometrically the specific activities of GSH-replenishing enzymes involved in GSH synthesis (gamma-glutamylcysteine synthetase, gamma-GCS), GSH regeneration (glutathione reductase, GR), and antioxidant protection (glutathione peroxidase, GPX; superoxide dismutase, SOD) in the cytosolic fraction of tumours and the surrounding normal tissue of 30 TCC patients. GSTP1-1 expression was also analyzed. RESULTS: We found a significant increase in the activity of both GSH-replenishing and antioxidant enzymes as well as enhanced GSTP1-1 expression in tumours in comparison with adjacent normal uroepithelium. Mean gamma-GCS and GR activities in tumours were about 4- and 2-fold higher, respectively, than in corresponding normal tissue. Expression of GSTP1 correlated significantly with GSH level and gamma-GCS and GR activities. GPX and SOD activities in TCC were also markedly increased. CONCLUSIONS: Enhanced GSH-replenishing pathways account for increased GSH levels in TCC. Upregulated GPX and SOD also contribute to high antioxidant potential in TCC. Under such conditions, expression of redox-sensitive GSTP1 protein is upregulated.     

Antioxidant status of children with steroid-sensitive nephrotic syndrome

Eighteen children with steroid-sensitive nephrotic syndrome (SSNS) were studied. The control group comprised 20 healthy children. The following indirect parameters of reactive oxygen species activity were determined in nephrotic patients during four stages of the disease (full relapse before prednisone administration, disappearance of proteinuria, prednisone cessation, unmaintained remission): plasma malondialdehyde (MDA) levels, copper/zinc superoxide dismutase (CuZn SOD) activity and glutathione peroxidase (GPX) activity in erythrocytes, reduced glutathione (GSH) and vitamin C levels in whole blood, and vitamin E level in serum. Increased MDA levels, reduced vitamin C levels, and enhanced CuZn SOD activity were found in relapse. GSH concentration was high during all four stages. Vitamin E level was also increased, parallel to the pattern of serum lipids. GPX activity remained low during the proteinuria stage and in remission. We conclude that the majority of abnormal findings can be attributed to the hyperlipidemia of NS. Low GPX activity may be a factor limiting the antioxidant capacity in NS. The present study is inconclusive regarding the role of free radicals in the proteinuria of NS. Received October 13, 1997; received in revised form April 13, 1998; accepted April 14, 1998     

Catalase, superoxide dismutase, and glutathione peroxidase activities in various rat tissues after carbon tetrachloride intoxication

Background. The aim of this study was to determine the possible relationship between the activity of three different antioxidant enzymes — peroxidase superoxide dismutase, catalase, and glutathione peroxidase — and carbon tetrachloride-induced injury. Methods. Male Wistar rats weighing 200–250g were used in the experiments. Rats of the experimental groups were given carbon tetrachloride 0.5ml/kg i.p. in olive oil (5mmol/kg body mass) for 1 or 3 days. Control group rats were injected with olive oil only for the same period. Brain, liver, kidney, and heart supernatants were used for measurement of superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPX) activities. Results. No statistically significant changes in SOD and GPX activities were observed in the liver after CCl₄ administration, but catalase activity was significantly increased after 24h and remained at that level during the course of the study. In the brain, SOD and catalase activities decreased after 24h of experiment, but GPX activity statistically significantly increased at all time points studied. Increased activities of SOD, catalase, and GPX were found in heart after CCl₄ intoxication. The CCl₄ injection in our experiment caused a reduction of SOD and catalase activities and increased GPX activity in the kidney. Conclusions. The results suggest that change in antioxidant enzyme activities may be relevant to the ability of the liver and other investigated organs to cope with oxidative stress during CCl₄ poisoning.     

Beneficial effects of aminoguanidine on radiotherapy‐induced kidney and testis injury

This experimental study was designed to investigate both protective and therapeutic effects of aminoguanidine (AG), on radiotherapy (RT)‐induced oxidative stress in kidney and testis. Forty rats were divided into five groups equally as follows: (i) control, (ii) RT, (iii) AG, (iv) AG+RT and (v) RT+AG group. Histopathological findings and biochemical evaluations, including tissue malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione (GSH), total oxidant status (TOS), total antioxidant capacity, oxidative stress index (OSI), blood urea nitrogen (BUN), serum creatinine (Cr) and testosterone levels, were determined. MDA, TOS and OSI were significantly higher in RT‐treated groups, whereas SOD, CAT, GPX and GSH were significantly lower in these groups when compared with the control rats in the kidney and testis tissue. AG treatment significantly decreased MDA, TOS and OSI levels and increased SOD, CAT, GPX and GSH levels, when compared to the RT‐treated groups in both kidney and testis tissue. BUN and Cr levels did not change among the groups, whereas testosterone levels were found as reduced in the RT‐treated rats. AG treatment significantly augmented these hazardous effects of RT on testis tissue. According to our results, AG has beneficial effects against RT‐induced kidney and testis injury.     

Ischemia-reperfusion injury in the liver during renal transplantation: does perfusion solution play any role?

The effect of ischemia-reperfusion (I/R) injury within a transplanted kidney has not been reported on the liver as a remote organ. One hypothesis is that there is no difference between kidney perfusion solutions regarding antioxidants in liver after an I/R injury. We used four pigs with Ringer's lactate (RL); four with university of Wisconsin (UW); and two in a control (C) group. A liver parenchymal biopsy was obtained before renal artery/vein solution clamping for 20 minutes. Either RL or UW solutions were infused through arterial cannulas for 20 minutes as previously described elsewhere. For the sham group, we used 0.9% NaCl. After reperfusion for 20 minutes, we obtained a second liver parenchymal biopsy. Measurements of superoxide dismutase (SOD), glutathione peroxidase (GP-x), and malondialdehyde (MDA) levels were compared using paired student t tests within groups and analysis of variance between groups. The results were expressed as mean values +/- SEM with P < .05 accepted as significant. Although GP-x, SOD, and MDA decreased after ischemia-perfusion-reperfusion injuries in all groups, except MDA in UW and SOD, and MDA in C groups; only the MDA for C was significant (P = .04) Comparing the groups, GP-x (P = .01) and MDA (P = .003) levels after ischemia-perfusion-reperfusion were significant while changes in SOD levels did not show any difference (P > .05). In a kidney transplantation model, the liver was affected during the ischemia-perfusion-reperfusion process as evidenced by antioxidant enzymes. The pathophysiology and clinical importance of this phenomenon requires further study. Comparing the perfusion solutions, no difference was found between RL and UW regarding their effects to decrease renal I/R injury on the liver in pigs.     

Alterations in free radical tissue-defense mechanisms in streptozocin-induced diabetes in rat. Effects of insulin treatment

We investigated the possible involvement of reactive oxygen radical-related processes in chronic (12-wk) diabetes induced in rats by streptozocin (STZ). Diabetes was associated with significantly increased activities of catalase (CAT), glutathione reductase (GSSG-RD), and CuZn-superoxide dismutase (SOD) in the pancreas and of CAT and GSSG-RD in the heart. On the other hand, the liver of diabetic rats showed a generalized decrease in CAT, glutathione peroxidase (GSH-PX), and SOD as well as in the levels of reduced glutathione (GSH). Diabetic kidney also showed decreases in CAT and SOD, but the activities of GSH-PX were increased. Insulin treatment (9-12 U/kg body wt) that was started after 8 wk of diabetes and continued for 4 wk reversed all of the foregoing alterations in tissue antioxidant status. Our results suggest the presence of increased oxidative stress in uncontrolled diabetes as manifested by the marked alterations in tissue antioxidant enzyme activities, the magnitude of which increased with the degree of emaciation. The complex patterns of changes observed in the various tissues examined are believed to be the result of compensatory increases in enzyme activities (usually involving enzymes whose activity in control tissues is low) and direct inhibitory effects, possibly resulting from an increased tissue-oxidant activity. Our findings support the view that tissue antioxidant status may be an important factor in the etiology of diabetes and its complications.     

抗氧化酶对隐睾生精细胞凋亡的影响

目的 :探讨超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT)、谷胱甘肽过氧化物酶 (GSHPx)对隐睾生精细胞凋亡的影响。　方法 :4 8只未成熟SD雄性大鼠随机分为隐睾组和对照组 ,于术后第 1、3、7d采集睾丸。TUNEL法检测其生精细胞凋亡 ;化学比色法测定其SOD、CAT、GSHPx的活性和丙二醛 (MDA)含量。　结果 :术后第 7d ,与对照组相比 ,隐睾重量、SOD活性、CAT活性和SOD/ (CAT +GSHPx)比值均显著降低 (P均 <0 .0 1) ,GSHPx的活性无显著变化 (P >0 .0 5 ) ,生精细胞凋亡指数和MDA含量均显著增加 (P均 <0 .0 1)。　结论 :隐睾生精细胞的凋亡与抗氧化酶活性的降低密切相关     

The effects of cyclosporine on antioxidant enzyme activities and malondialdehyde levels in rabbit hepatic tissues

Possible molecular mechanisms leading to cyclosporine-induced hepatotoxicity has not been cleared yet. Therefore, investigation of antioxidant status of hepatic tissues exposed to cyclosporine A (CsA) and of free radical involvement in the CsA-induced hepatotoxicity seems of importance. For this aim, 20 rabbits were used in the study. In each group (control, CsA, CsA plus vitamin and, vitamin only) there were 5 animals. CsA was given orally (25 mg/kg/day) for 10 days. Vitamins E (100 mg/kg/ day) and C (200 mg/kg/day) combination was injected intramuscularly. After 10th day, animals were killed, and livers were prepared for the enzymatic assays. Activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) and, malondialdehyde (MDA) levels were determined in the supernatant fractions. Lowered SOD, unchanged GSH-Px and, increased CAT activities and MDA levels were detected in hepatic tissues of rabbits treated with CsA as compared with controls. In the CsA plus vitamin group, SOD activity was found to be higher, GSH-Px and CAT activities unchanged and MDA levels lower than the CsA group. In the vitamin-treated group, all of the enzyme activities were higher than the controls but MDA levels were unchanged. Correlation analysis revealed some significant differences between the groups. Results suggest that cyclosporine impairs the antioxidant defense system and thus, leads to oxidant stress and peroxidation in rabbit hepatic tissues. It has been established that this process can be prevented by antioxidant vitamin supplementation.     

Alterations of antioxidant trace elements (Zn, Se, Cu) and related metallo-enzymes in plasma and tissues following burn injury in rats

To improve the nutritional support for burn patients, we evaluated the alterations of selenium, zinc and copper (Se, Zn and Cu) and their possible contributions to an unbalanced antioxidant response to burn injury. These trace elements and the related antioxidant enzymes, glutathione peroxidase (GPx) and superoxide dismutase (SOD), were studied both in plasma (or serum) and tissues of 20% total body surface area (TBSA) burned rats for 10 days. While plasma Se and serum Zn levels significantly decreased 6 h after burn injury, serum Cu levels increased after 1 day and remained elevated the following 9 days. Selenium levels increased in kidney but decreased progressively in liver. The hepatic Zn and Cu concentrations followed a biphasic increase following burn injury. During the first day, GPx activity decreased in plasma and remained unchanged in the organs, except for a moderate diminution in the liver. Liver Cu/Zn SOD activity increased from 6 h to 4 days. In summary, following burn injury, copper and zinc were redistributed to the liver and selenium to the kidney with non-detectable changes in the muscle and brain. Changes in antioxidant enzyme activities following burn injury were significant mainly in the plasma. Early combined antioxidant supplementation to maintain and restore antioxidant status in burn patients requires further study.     

Influence of Acute Exercise on Oxidative Stress in Chronic Smokers

The relative oxidative insult caused by exercise and smoking on biological systems are well documented, however, their cumulative influence needs to be clarified. In order to examine the collective effects of exercise and smoking on oxidant and antioxidant parameters, young male smokers (n=10) and non-smokers (n=10) made to perform a negative slope (10%) cycling exercise for 30 minutes at individual load equivalent to 60% maximal oxygen consumption (VO₂max). Pre- and post-exercise (post-ex) haematocrit, haemoglobin, white blood cells, plasma malondialdehyde (MDA) levels, protein carbonyl formation and non-HDL oxidation, erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities, serum ceruloplasmin (CER) and urinary cotinine concentrations were evaluated. Pre-ex CER and urinary cotinine concentrations of smokers were significantly higher (p<0.05 and p<0.01, respectively) compared to that of non-smokers and pre-ex CER concentrations were significantly correlated with cotinine levels in all subjects (p<0.05). Significant (p<0.01) increases were observed in non-HDL oxidation following the exercise in both groups and the elevations were more pronounced in smokers. Pre-ex SOD and GPX activities were not different between the two groups, however post-ex enzyme activities were significantly reduced in smokers (p<0.05). MDA and protein carbonyl concentrations were not different between the two groups and there were not any significant changes due to exercise.In conclusion, according to the results of the present study, we suggest that erythrocyte antioxidants SOD and GPX and plasma non-HDL are more prone to the possible oxidant damage of acute physical exercise in chronic smokers.Key Words: Exercise, smoking, protein oxidation, non-HDL oxidation, superoxide dismutase, glutathione peroxidase     

Markers of oxidative stress after renal transplantation

Abstract An increased degree of oxidative stress (OS) in chronic renal failure (CRF) and a possible role of free radicals in CRF have already been described. However, data on OS after renal transplantation are scarce. The aim of the present study was to estimate the degree of OS in renal transplant patients. The study included four groups: 1) 15 haemodialysis patients (HD group), 2) 11 renal transplant patients with stable function (SF group), 3) 12 renal transplant patients with chronic biopsy-proven rejection (CR group), and 4) 10 healthy controls (C group). Markers of OS (malondialdehyde and thiol group levels) and antioxidant activity (glutathione peroxidase and Cu, Zn-su-peroxide dismutase) were determined in plasma and in red blood cells of all examined individuals. After successful renal transplantation a significant improvement, but not normalization, of antioxidant enzyme activities accompanied by significantly reduced lipid peroxidation were found. In the CR group the degree of OS was increased, and our results suggest that OS may be a relevant pathophysiological factor for CR development.     

Altered antioxidant capacity in human renal cell carcinoma: role of glutathione associated enzymes

PURPOSE: We aimed to discern the role of glutathione (GSH) associated enzymes in maintaining high GSH levels in renal cell carcinoma (RCC) of the clear cell type and analyze RCC enzyme antioxidant capacity. Since changes in cellular redox balance in RCC might also be related to alterations of glutathione S-transferase (GST) phenotype, GST class alpha and pi expression was also explored. METHODS AND MATERIALS: Human kidney specimens of tumor and distant nontumor regions were obtained from 15 patients with RCC at the time of surgery. The activities of GSH-replenishing enzymes, gamma-glutamylcysteine synthetase (gamma-GCS), gamma-glutamyl transferase (gamma-GT), and glutathione reductase (GR), as well as the activities of antioxidant enzymes glutathione peroxidase (GPX) and catalase (CAT) were determined spectrophotometrically. GST alpha and pi class expression was determined by immunoblot. RESULTS: In the course of renal cancerization, significant changes appear in the activities of GSH-replenishing and antioxidant enzymes. The activity of the key enzyme of GSH synthesis, gamma-GCS, is up-regulated (P < 0.001), while the activities of gamma-GT and GR are down-regulated in renal tumors compared to nontumor tissue (P < 0.001 and P < 0.05, respectively). Activities of GPX and CAT were also down-regulated (P < 0.001 and P < 0.05, respectively) in RCC. Changes in enzyme antioxidant capacity in RCC were associated with decreased GST class alpha (P < 0.001) and unchanged GST pi expression at the protein level. CONCLUSIONS: Changes in redox status in RCC as a consequence of decreased enzyme antioxidant capacity, together with altered GST alpha expression, may be important factors in development and tumor growth. The up-regulation of gamma-GCS and high levels of GSH in RCC may be an attempt to limit injury caused by oxidative stress.     

The impact of orthopedic device associated with carbonated hydroxyapatite on the oxidative balance: experimental study of bone healing rabbit model

Orthopedic devices are used in pathologic disorder as an adjunct to bone grafts to provide immediate structural stability. Unfortunately, the use of metallic devices has some complications. This study aimed to characterize the oxidative stress biomarker and the antioxidant enzyme profiles during bone regeneration. New Zealand White rabbits were divided into 4 groups: Group (I) was used as control (T), Groups II, III, and IV were used, respectively, as implanted tissue with carbonated hydroxyapatite (CHA), carbonated hydroxyapatite associated with external fixator (CHA + EF), and presenting empty defects (ED). Grafted bone tissues were carefully removed to measure malondialdehyde (MDA) concentration, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase activities (GPx). Our results showed that 4 weeks after operation, treatment of rabbits with CHA + EF showed a significantly higher malondialdehyde (MDA) concentration when compared to that of control group. The SOD, CAT, and GPx in CHA + EF group showed significantly lower activities when compared to those in control group. Eight weeks after surgery, the CHA + EF group presented a lower concentration of MDA as compared to those seen after the first 4 weeks after surgery. On the other hand, the SOD, CAT, and GPx showed a higher activity when compared with the same group. Consequently, MDA concentration and the antioxidant enzyme activities were not significant (p > 0.05) when compared to those in control group rabbits. Histologic sampling has demonstrated successful time-patterned resorption accompanied by bone replacement and remodeling. These results suggest that there was a temporary increase in the oxidative marker level in CHA + EF healing bone and the 8-week period was sufficient to re-establish oxidant–antioxidant balance accompanied by bone repair in the tibia rabbit model.     

兔重度创伤后急性微量元素变化与多器官功能障碍综合征及死亡的关系

目的：探讨严重创伤后微量元素（TE）变化与继发多器官功能障碍综合征（MODS）及死亡的关系.方法：建立创伤严重度评分（ISS）为22分的严重创伤家兔模型,观察伤后12 h、36 h、60h、6 d、9 d、14 d、21 d、28 d家兔的内脏形态学改变,同步检测血Zn、Se、Cu、Fe含量及其相关酶和产物GPX、SOD、MPO、MDA含量变化,以及血AST、ALT、Cr、BUN等生化指标含量变化.结果：重伤后血Zn、Fe、Se含量明显下降,持续2～3周.GPx活性明显下降,持续1周;SOD活性伤后1 d下降,之后快速升高;MPO活性1周内升高,之后逐渐降至正常水平;MDA含量第3天开始升高,第6天达高峰.严重创伤组家兔伤后3～6 d死亡率为26%,血生化指标符合MODS,病理学检查符合MOF改变.结论：严重创伤可引发血Se、Fe、Zn等急性TE缺乏及其相关酶活性和代谢产物变化,提示TE可能参与MODS的发生过程.     

Perioperative levels of glutathione reductase in liver transplant recipients with hepatitis C virus cirrhosis

Surgical intervention causes oxidative stress leading to an adaptive responses by the body. To evaluate changes in the defense capacity of antioxidant enzymes, we determined the activity of glutathione reductase (GR) levels among liver transplant recipients with due to hepatitis C virus cirrhosis. The study was performed in 22 patients (16 males and 6 females) of average ages 52.63 ± 5.49 years for males and 59.67 ± 5.65 years for females. Blood samples for glutathione reductase activity were drawn on admission before as well as at 1, 6, and 12 h and 1, 2, 3, 5 and 7 days after the liver transplantation.Perioperative glutathione reductase levels were significant (P = .014) over the period using Bonferroni tests. GR activity reached a maximum (15.6112 ± 6.56035 nmol/mg protein) at 3 days after liver transplantation (T3d) (P = .001). The increased GR activity values detected perioperatively indicated scavenging of reactive oxygen species generated after liver transplantation of hepatitis C virus cirrhosis patients.