Antioxidant Defense System In Patients Research Articles

The effect of major depressive disorder comorbidity on ischemia-modified albumin levels, a marker of oxidative stress, and antioxidant defense system in patients with obsessive compulsive disorder.

The aim of this study was to examine the levels of oxidant and antioxidant markers in patients with obsessive-compulsive disorder (OCD) and to investigate whether these levels change in the presence of major depressive disorder (MDD) comorbidity. This study was completed with 23 OCD patients with MDD comorbidity (OCD+MDD), 21 OCD patients without MDD comorbidity (OCD-MDD) and 21 healthy controls. Oxidative stress levels of the cases' were determined by ischemia modified albumin (IMA) and malondialdehyde (MDA) measurements and antioxidant levels were determined by superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) measurements. One-way analysis of variance (ANOVA) and unpaired Student's t-test were used to compare the study groups. Post hoc Bonferroni test was used for the degree of significance between groups, and repeated measures analysis of covariance (ANCOVA) was used to investigate the effect of age and gender. IMA and MDA levels were significantly higher in the OCD group compared to the control group, and SOD, CAT and GSH-Px levels were lower in the OCD group compared to the control group (p<0.01). IMA levels were significantly higher in the OCD+MDD group compared to the OCD-MDD group, while SOD, CAT and GSH-Px levels were significantly lower in the OCD+MDD group compared to the OCD-MDD group (p<0101). MDA levels were significantly higher in the OCD+MDD group compared to the OCD-MDD group (p=0.009). When the entire OCD patient group was examined, significant, powerful, positive correlations were observed between Y-BOCS and HDRS scores and IMA and MDA, and significant powerful negative correlations between Y-BOCS and HDRS scores and SOD, CAT, and GSH-Px (p<0.001 for all). In OCD+MDD group, oxidative stress markers increased significantly in parallel with the severity of depression, while antioxidant levels decreased (p=0.003 for IMA, p<0.001 for others). We believe that parameters indicating impaired oxidant/antioxidant balance in patients with obsessive-compulsive disorder may help to elucidate the cause of the disease and may be potentially useful biomarkers in the diagnosis and determination of the severity of comorbid MDD.

Lipid peroxidation and antioxidant defense system in patients with kidney cancer

Purpose of the study: to assess the state of lipid peroxidation processes in patients with kidney cancer in relation to the clinical factors of the prognosis of the disease and against the background of surgical intervention.Material and methods. For the study, we used blood plasma samples from 300 patients with kidney cancer T1–4N 0–1M0–1, obtained before surgery and 8–9 days after surgery. Oxidative stress was assessed by the intensity of free radical processes by the method of induced biochemiluminescence on the BKhL-07 biochemiluminometer apparatus (Medozons Co., Russia), the activity of lipid peroxidation processes was assessed by the accumulation of initial products in the blood plasma – diene conjugates (DC), triene conjugates (TC) and fial Schiff bases (OSh) according to I. A. Volchegorsky et al. method. (1989). Statistical processing of the results was carried out using Statistica 12 and Microsoft Offie Excel 2010 programs.Results. In patients with kidney cancer, there was a decrease in the level of DC, an increase in OSh and the ratio of Osh / (DC + TC) compared with the control (p ≤ 0.05), against the background of depletion of the resources of the antioxidant defense system. The content of DC did not differ from the norm with the size of the primary tumor of the kidney pT1–pT2 and decreased (p ≤ 0.05) in the case of the presence of the tumor pT3–pT4. At the same time, there was an increase in the OSh content (p ≤ 0.05). In patients with thrombi in the inferior vena cava system, a decrease in the level of DC was observed (p ≤ 0.05), the OSh level did not differ from that of healthy individuals. In the postoperative period, there was an increase in the content of DC (p ≤ 0.05) and a decrease in the Osh / (DC + TC) coeffiient (p ≤ 0.05) compared with the initial level.Conclusion. Kidney cancer is accompanied by the activation of free radical oxidation processes against the background of depletion of the resources of the antioxidant defense system. Changes in the pro-antioxidant homeostasis are interrelated with the size of the primary tumor and the presence of a tumor thrombus. In the postoperative period, the activity of free radical oxidation processes in the patient’s body decreases.

Glutathione-related antioxidant defense system in patients with hypertensive retinopathy.

Objective: To analyze the glutathione antioxidant defense system changes in the tear and serum of patients with hypertensive retinopathy (HR) and to establish whether there is an interdependence between their levels and HR degree. Methods: 90 patients were split into three groups according to the Keith-Wagner-Barker grading of HR: GI–36 patients; GII–35 patients; GIII–19 patients. The concentration of reduced glutathione (GSH) and activities of glutathione peroxidase (GPx) and glutathione reductase (GR) in tear and serum were measured. Results were analyzed by ANOVA, followed by Bonferroni post hoc test. The Spearman correlation coefficient was calculated (p≤0.05 statistically significant).Results: In serum, the GSH level and GPx activity were not statistically changed between groups with HR degree advancement, unlike the GR activity that was statistically diminished (p=0.018). The values of the studied markers in the tear showed a decrease with the progression of the HR degree. Only serum GSH level correlated with the tear one (r=-0.361, p=0.000), while the enzymes activity did not. A correlation of GPx and GR activity (r=0.417, p=0.000) was identified in tear, while in serum - of GPx activity and GSH level (r=409, p=0.000). Tear GPx and GR levels correlated significantly but with low power with HR degree (r=0.299, p=0.004/ r=0.299, p=0.004).Conclusion: Statistically significant elevation in tear GPx and GR activity and a tendency of GSH level increase was revealed, being attested, and a direct correlation between GPx and GR activity, as well as of their activity with the HR degree. In serum, the GSH level and the GPx activity did not change accurately, while the GR activity diminished significantly, the identified decrease being correlated with the HR degree. Abbreviations: HR = hypertensive retinopathy, HTN = hypertension, GSH = reduced glutathione, GPx = glutathione peroxidase, GR = glutathione reductase, GGR = gamma-glutamyl transferase, ROSs = reactive species of oxygen, OS = oxidative stress

Ферментативна та неферментативна складові системи антиоксидантного захисту у пацієнтів молодого віку з гастроезофагеальною рефлюксною хворобою та автоімунним тиреоїдитом

Antioxidant defense is considered in the context of a universal system, which, together with the components of the immune system, provides hemodynamic balance and antigenic homeostasis of the body, that is, the work of this system, represented by two practically independent links. The first line of the antioxidant system, the work of which is associated with the activity of superoxide dismutase, catalase, ceruloplasmin and a number of other enzymatic and non-enzymatic components, is considered an initial barrier, provides support at a constant controlled level of free radical oxidation. However, there is insufficient data in previous studies regarding the antioxidant defense system in patients with gastrointestinal disorders associated with thyroid disease. The purpose of the work was to establish the state of the antioxidant system in terms of total antioxidant activity and 8-isoprostane in young people with gastroesophageal reflux disease and autoimmune thyroiditis. Material and methods. The work involved 120 people with a combined course of gastroesophageal reflux disease and autoimmune thyroiditis at the age from 18 to 25 years. All patients had the same social status (students), which made it possible to equalize both physical and emotional stress, peak and stressful situations. Results and discussion. We examined the indicators of total antioxidant activity: the aggregate value of enzymes of the first level of the antioxidant system and 8-isoprostane, the level of the non-enzymatic link in antioxidant protection. These indicators depended on the morphological form of damage to the mucous membrane of the esophagus: they were more expressive in the erosive form of esophagitis. Thus, the combined course of gastroesophageal reflux disease and autoimmune thyroiditis is accompanied by changes in the indicators of the antioxidant system as a result of an active inflammatory process in the esophageal mucosa. There is a decrease in the total antioxidant activity, the first line of the antioxidant system, the value of which depends on morphological changes in the esophageal mucosa. Conclusion. An active inflammatory process in patients with gastroesophageal reflux disease and autoimmune thyroiditis leads to an increase in 8-isoprostane, an indicator of a non-enzymatic link in the antioxidant defense system

Selenium Nutritional Status and Glutathione Peroxidase Activity and Its Relationship with Hemodialysis Time in Individuals Living in a Brazilian Region with Selenium-Rich Soil.

Suboptimal selenium status may impair the antioxidant defense system in patients undergoing hemodialysis, compromising the selenoenzyme glutathione peroxidase activity. To evaluate the association between the duration of hemodialysis, nutritional selenium status, glutathione peroxidase activity (GPx), and thiobarbituric acid reactive substance (TBARS) levels in patients with chronic renal failure undergoing hemodialysis in a region of selenium-rich soils (Ceará, Northeast Brazil). The case-control study of 75 individuals aged 18 to 88 years was allocated between two groups: hemodialysis (n = 41) and control (n = 34). Plasma and erythrocytes selenium levels were determined by inductively coupled plasma optical emission spectrometry. The GPx activity and TBARS levels were also evaluated. In addition, the hemodialysis group was stratified according to the duration of treatment (≤ 59 months and ≥ 60 months). The Mann-Whitney test, Student's t test, and Pearson's or Spearman's correlation were applied according to the data distribution. Moreover, a quantile regression was performed. The significance level (p) was < 0.05. The hemodialysis group had lower selenium levels in their plasma and erythrocytes than the control group (p < 0.001). However, there was no difference in the GPx activity between the groups. Furthermore, an association between the hemodialysis group and selenium levels in plasma (coefficient - 16,343, p < 0.001) and erythrocytes (coefficient - 7839, p = 0.003) was observed by quantile regression, independent of age, sex, and body-mass index. In individuals who had undergone treatment for 60 months or more, GPx activity was lower (p = 0.026) and TBARS levels higher (p = 0.011) than in those who had undergone treatment for less than 60 months. The status of selenium was reduced in the hemodialysis group compared to the control group. The lower GPx activity and higher levels of TBARS in individuals who had undergone treatment for 60 months or more correlated with greater oxidative stress.

Assessment and comparison of the antioxidant defense system in patients with type 2 diabetes, diabetic nephropathy and healthy people: A case–control study

Findings of previous studies in the field of antioxidant defense system in patients with type 2 diabetes (T2DM), diabetic nephropathy (DM) are limited and conflicting. Therefore, we evaluated the antioxidant defense system status in type 2 diabetes patients, diabetic nephropathy and healthy subjects in Iranian population. This population-based case-control study was conducted in 2019 and included 30 individuals with T2DM and 30 patients with DN, as the case groups and 30 healthy subjects for the control group. Individuals entered to the study for case group were diagnosed as T2DM patients based on fast glucose blood tests (FGB) (≥126mg/dL) and HbA1 (≥6.5%). DN was defined based on these tests and macroalbuminuria (>300mg/day). Serum was carefully separated and antioxidant defense system status was estimated. Dietary intakes were evaluated by using a food frequency questionnaire (FFQ). Energy intake in control group was higher than case groups; BMI was higher in the DN group compared to the other groups. Significantly higher levels of MDA were observed in T2DM patients compared to control group in crude model (1.255 vs. 1.079nmol/L; P=0.006). The same results were shown after adjustment for potential confounders (1.256 vs. 1.085nmol/L; P=0.022). Total antioxidant capacity (TAC) was less in case groups compared with control group; level of catalase (CTL) and superoxide dismutase enzymes comparisons showed that DN patients had higher level than control group, but these associations were not significant. We found that MDA levels were significantly higher in T2DM patients compared to control group. Level of TAC was less in case groups in comparison to controls. SOD and CTL levels were higher in DN compared to controls; these associations were not significant.

Assessment of the intensity of lipid peroxidation and catalase activity in the blood-erythrocyte serum system in patients with laryngeal cancer

Aim: To evaluate the intensity of lipid peroxidation and the activity of catalase in patients with laryngeal cancer. Materials and Methods: Samples of blood serum and erythrocytes from 40 patients with laryngeal cancer of stages II and III and 20 healthy volunteers were investigated. Results: The level of TBA-positive products and diene conjugates in blood serum samples of stage II and III patients with laryngeal cancer was increased than that of control. In the same time catalase activity was significantly reduced. In the erythrocytes of patients in both groups the level of diene conjugates and catalase activity was higher than that of control. The level of TBA-positive products increased only in patients with III stage disease. Our results indicate the intensification of free-radical oxidation against the background of the functional stress of the antioxidant defense system in patients with laryngeal cancer, as well as the violation of the structural and functional state of erythrocyte plasma membranes, which is manifested in the activation of lipid peroxidation. This indicates about the formation of a complex of disorders, which can play a significant role in the development and deepening of the pathological process.

The role of endogenous intoxication syndrome and the activity of the antioxidant protection system in the survival of generalized parodontitis in nuclear disease patients with toxic hepatitis

The role of endogenous intoxication syndrome and the activity of the antioxidant protection system in the survival of generalized parodontitis in nuclear disease patients with toxic hepatitis

Comparative analysis of plasma total antioxidant capacity in patients with hyperglycemia and hyperglycemia plus dyslipidemia

AimsThe aim of this study was to measure plasma total antioxidant capacity (TAC) level and superoxide dismutase (SOD) activity in order to assess the oxidative stress status and the antioxidant defense system in patients with hyperglycemia and both hyperglycemia and dyslipidemia. Materials and methodsSixty blood samples of hyperglycemia, 60 blood samples of both hyperglycemia and dyslipidemia and 60 blood samples of normoglycemia and normolipidemia (controls) were collected into study. All samples were measured for the levels of plasma TAC and SOD by colorimetric method using microtiter-plate reader. ResultsPlasma TAC significantly decreased in patients with hyperglycemia (0.42 ± 0.1 mM) and both hyperglycemia and dyslipidemia 0.41 ± 0.1 mM) compared to those of controls (0.47 ± 0.14) (P < 0.05), whereas plasma SOD significantly increased in patients with hyperglycemia (81.0 ± 17.9 U/ml) and both hyperglycemia and dyslipidemia (83.7 ± 21.3 U/ml) compared to those of controls (73.7 ± 17.4 U/ml) (P < 0.05). However, the levels of plasma TAC and SOD had no significant difference between patients with hyperglycemia and both hyperglycemia and dyslipidemia (P > 0.05). ConclusionsThe present study showed the significant difference of plasma TAC and SOD levels in hyperglycemic patients with and without dyslipidemia compared to those of controls. There was no additive or synergistic effect in terms of decreased plasma TAC levels and elevated SOD activities between hyperglycemic patients with and without dyslipidemia.

Zinc and Copper in antioxidant defense system in patients with chronic nonbacterial prostatitis

Among men of working age chronic prostatitis is the most frequent urological sickness, and characteristic symptoms of it are frequent reason of the urological recourse. Therefore this excuses a search for new methods of examination and treatment of the patients with this pathology.The objective: purpose of our research was studying of level of Zinc and Copper in blood and ejaculate and specialty of antioxidic defense of the patients with chronic nonbacterial prostatitis.Materials and methods. Under supervision were 120 patients with chronic nonbacterial prostatitis, among them 60 patients with inflammatory chronic pelvic pain syndrome(category IIIA) and 60 patients with noninflammatory chronic pelvic pain syndrome (category IIIB). Microelements Zinc and Copper in whole blood an ejaculate were determined using atomic absorption spectrophotometry on C-115 PC. State of antioxidant defense was judged considering quantification of Catalase after A. Bach and S. Zubkova and Superoxide Dismutase.Results. A certain decrease of Zinc and increase of Copper were observed in both groups of patients with chronic nonbacterial prostatitis. More expressed decrease of Zinc and increase of Copper were observed in patients with inflammatory chronic pelvic pain syndrome. Also it was noted that with long duration of chronic nonbacterial prostatitis takes place the antioxidant enzymes level decrease. More expressed decrease was observed in patients with inflammatory chronic pelvic pain syndrome. As a result of correlation analysis it was found that there is certain dependence between level of Zinc, Copper in blood and antioxidant defense enzymes.Conclusion. With chronic nonbacterial prostatitis were observed decrease of Zinc and increase of Copper levels in blood as well as in ejaculate of the patients. More intense decrease of Zinc and increase of Copper were noted in patients with inflammatory chronic pelvic pain syndrome. Metabolic changes with shortage of Zinc and excess of Copper correlate with antioxidant system disbalance, that is with antioxidant defense level decrease.

Role of Antioxidants in the Management Diabetes Mellitus

Diabetes mellitus (DM), commonly referred to as diabetes, is a group of metabolic diseases in which there are high blood sugar levels over a prolonged period. Symptoms of high blood sugar include frequent urination, increased thirst and increased hunger. If left untreated, diabetes can cause many complications. Acute complications can include diabetic ketoacidosis, nonketotic hyperosmolar coma, or death. Serious long-term complications include heart disease, stroke, chronic kidney failure, foot ulcers, and damage to the eyes. Oxidative stress plays a major role in the pathogenesis and development of complications of both types of DM. However, the exact mechanism by which oxidative stress could contribute to and accelerate the development of complications in diabetic mellitus is only partly known and remains to be clarified. On the one hand, hyperglycemia induces free radicals; on the other hand, it impairs the endogenous antioxidant defense system in patients with diabetes. Endogenous antioxidant defense mechanisms include both enzymatic and non-enzymatic pathways. Their functions in human cells are to counter balance toxic reactive oxygen species (ROS). Common antioxidants include the vitamins A, C, and E, glutathione (GSH), and the enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GRx). Many natural antioxidants can be used in lowering blood glucose level. This review describes the importance of natural antioxidants to be included in the diet to reduce the hyperglycemic effect.

The condition of the antioxidant defense system in patients with nonalcoholic steatohepatitis, combined with chronic obstructive pulmonary disease

The condition of the antioxidant defense system in patients with nonalcoholic steatohepatitis, combined with chronic obstructive pulmonary disease

A Case-Control Study of Involvement of Oxidative DNA Damage and Alteration of Antioxidant Defense System in Patients with Basal Cell Carcinoma: Modulation by Tumor Removal.

Oxidative damage has been suggested to play a role in the pathogenesis of basal cell carcinoma (BCC). This study illustrated an involvement of oxidative DNA damage and changes in antioxidant defenses in BCC by conducting a case-control study (24 controls and 24 BCC patients) and assessing urinary 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxo-dGuo), plasma antioxidant defenses including catalase (CAT), glutathione peroxidase (GPx), NQO1, and total superoxide dismutase (SOD) activities, and glutathione (GSH) levels before surgery and 1 month after surgery. 8-oxo-dGuo expressions as well as protein and mRNA expressions of DNA repair enzyme hOGG1 and antioxidant defenses (CAT, GCLC, GPx, Nrf2, and MnSOD) in nonneoplastic epidermis of control and BCC tissues were also determined. This study observed induction in urinary 8-oxo-dGuo, increased 8-oxo-dGuo expression, and reduced hOGG1 protein and mRNA in BCC tissues, decreased activities of CAT, GPx, and NQO1, but elevated SOD activities and GSH levels in BCC patients and reduction of all antioxidant proteins and genes studied in BCC tissues. Furthermore, decreased plasma antioxidant activities in BCC patients were restored at 1 month after operation compared with preoperative levels. Herein, we concluded that BCC patients were associated with oxidative DNA damage and depletion of antioxidant defenses and surgical removal of BCC correlated with improved redox status.

143 - A Case-Control Study of Involvement of Oxidative DNA Damage and Alteration of Antioxidant Defense System in Patients with Basal Cell Carcinoma: Effect of Tumor Removal

143 - A Case-Control Study of Involvement of Oxidative DNA Damage and Alteration of Antioxidant Defense System in Patients with Basal Cell Carcinoma: Effect of Tumor Removal

Changes in Glucose-6-phosphate Dehydrogenase Activity in Paroxysmal Atrial Fibrillation

Abstract Background: The antioxidant defense system has been subject to investigations in various cardiovascular diseases. The studies of its status in paroxysmal atrial fibrillation are scarce. The enzyme glucose-6-phosphate dehydrogenase is the main source of reducing equivalents and its activity is crucial for the antioxidant defense system of the cell. Purpose: To study the activity of glucose-6-phosphate dehydrogenase in dynamics as an indicator of the antioxidant defense system in patients with paroxysmal atrial fibrillation (<48 hours). Patients and methods: The enzyme was studied in erythrocytes of 51 patients (59.84±1.60, 26 males) immediately after hospitalization, 24 hours and 28 days after sinus rhythm restoration. It included also 52 healthy controls (59.50±1.46, 26 males), matching the patients by gender and age. The rhythm regulation was achieved by propafenone . The enzyme activity was determined spectrophotometrically. Results : The mean duration of atrial fibrillation episodes prior to hospitalization was 8.1 hours, the majority of the patients being hospitalized on the 5

Antioxidant Status and Oxidative Stress Markers in Pancreatic Cancer and Chronic Pancreatitis

Oxidative stress has been implicated in the pathogenesis of chronic pancreatitis (CP) and pancreatic cancer (PC). The study aim was to assess the oxidative stress markers and antioxidant defense system in patients with CP and those with PC. Activities of superoxide dismutase 1 (SOD1), catalase (CAT), glutathione peroxidase 1 (GPX1), glutathione reductase (GR), arylesterase (PON1-A) and lactonase (PON1-L) activities of paraoxonase 1 (PON1) and concentrations of reduced glutathione, conjugated dienes in low-density lipoprotein (CD/LDL) and oxidized LDL (ox-LDL/LDL) were assessed in 50 PC and 50 CP patients and 50 age and sex-matched controls. Comparison of PC and CP groups to controls found the following changes: glutathione peroxidase 1 (GPX1) (-20.2%, -25.5%; P < 0.001), glutathione reductase (GR) (-9.5%, -11.9%; P < 0.05), SOD1 (+22.9%; P < 0.01), CAT (-10.6%; P < 0.05), PON1-A (-34.3%, -16.0%; P < 0.001), PON1-L (-44.2%; -17.0%; P < 0.01), conjugated dienes in LDL (CD/LDL) (+20%, +33.3%; P < 0.05) and ox-LDL/LDL (+42.2%, +14.4%; P < 0.05). The patients with PC had changed activities and levels of SOD1 (+24.2%), CAT (-10.4); P < 0.01), PON1-A (-21.7%), PON1-L (-32.9%), and ox-LDL/LDL (+24.3%); (all P < 0.01) compared with the patients with CP. Reduced antioxidant defense system capacity and increased markers of oxidative stress were found in PC and CP. PON1-L and CAT activities, along with ox-LDL/LDL levels, were the independent factors differentiating the patients with PC from the patients with CP.

Increased oxidative DNA damage and impaired antioxidant defense system in patients with gastrointestinal cancer

BackgroundHighly active intermediates are formed in aerobic metabolism which in turn leads to cellular damage. It is increasingly proposed that free radicals play a key role in human cancer development. The aim of this study was to investigate changes in 8-hydroxy-deoxyguanosine, nitrite+nitrate, total glutathione, total antioxidant capacity levels and superoxide dismutase, catalase, glutathione peroxidase activities in operative patients with gastrointestinal cancer before and after surgery and compare with inoperative patients. MethodsOxidative stress parameters were measured in 59 gastrointestinal cancer patients and 20 controls. 8-hydroxy-deoxyguanosine was quantitated by Elisa method. Superoxide dismutase, catalase, glutathione peroxidase were assayed with colorimetric methods; Nitrite+nitrate, total glutathione and total antioxidant capacity were assayed with spectrophotometric methods. Results8-hydroxy-deoxyguanosine levels in cancer patients were higher than those of control group (p<0.01). Similarly, glutathione levels were increased compared with controls (p<0.01). However, nitrite+nitrate, total antioxidant capacity levels and superoxide dismutase and catalase activities were decreased in cancer patients compared with controls (p<0.01, p<0.01, p<0.05, p<0.01, respectively). The patients were divided into two groups; operative (n=30) and inoperative (n=29). A significant difference was found in inoperative group compared with postoperative group according to glutathione peroxidase activity (p<0.05). DiscussionOur results demonstrate that the oxidant/antioxidant balance was altered in favor of free radicals and DNA damage in gastrointestinal cancer patients. Significant increases in 8-hydroxy-deoxyguanosine, glutathione and decreases in nitrite+nitrate, SOD, CAT activities and antioxidant molecules suggest the possible involvement of oxidative stress in gastrointestinal cancer. Glutathione peroxidase activities in postoperative patients were higher compared to inoperative patients.

The role of oxidative stress and antioxidants in diabetic complications.

Diabetes is considered to be one of the most common chronic diseases worldwide. There is a growing scientific and public interest in connecting oxidative stress with a variety of pathological conditions including diabetes mellitus (DM) as well as other human diseases. Previous experimental and clinical studies report that oxidative stress plays a major role in the pathogenesis and development of complications of both types of DM. However, the exact mechanism by which oxidative stress could contribute to and accelerate the development of complications in diabetic mellitus is only partly known and remains to be clarified. On the one hand, hyperglycemia induces free radicals; on the other hand, it impairs the endogenous antioxidant defense system in patients with diabetes. Endogenous antioxidant defense mechanisms include both enzymatic and non-enzymatic pathways. Their functions in human cells are to counterbalance toxic reactive oxygen species (ROS). Common antioxidants include the vitamins A, C, and E, glutathione (GSH), and the enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GRx). This review describes the importance of endogenous antioxidant defense systems, their relationship to several pathophysiological processes and their possible therapeutic implications in vivo.

P423 State of lipid preoxidation and antioxidant defense system in patients with autoimmune miscarriages after ozone therapy

P423 State of lipid preoxidation and antioxidant defense system in patients with autoimmune miscarriages after ozone therapy

Erythrocyte Antioxidant Defense System in Patients with Chronic Renal Failure According to the Hemodialysis Conditions

Patients suffering from chronic renal failure (CRF) are exposed to increased oxidative stress generated by uremic toxins, factors connected with hemodialysis, chronic inflammatory state, lack of vitamins A, E and selenium, advanced age, and parenteral iron administration. Their antioxidative system is inefficient. In erythrocytes, hexosemonophosphate (HMP) cycle does not assure an adequate amount of reductive equivalents (NADPH) necessary to restore reduced glutathione (GSH), an important free radical scavenger. Hemodialysis treatment also causes a large loss of glucose, which is the basic substrate for that metabolic pathway. The object of the research was to establish the influence of glucose present in dialysate on antioxidant defense system in red blood cells. A group of 51 patients undergoing regular hemodialysis using glucose (26 subjects, GL+ HD) or non-glucose fluid (25 subjects, GL- HD) was studied. The GSH concentration, glucose-6-phosphate dehydrogenase (G-6-P DH) and glutathione reductase (GSSG-R) activities were determined. Glucose concentration before and after the hemodialysis session was also measured. The activity of G-6-P DH was significantly higher in GL+ HD both before (p = 0.000) and after (p = 0.0002) the dialysis treatment compared to GL- HD, respectively, and to the healthy subjects (p = 0.000). The hemodialysis session caused a decrease in the activity of the enzyme in GL+ HD from 4.91 +/- 1.53 to 4.42 +/- 1.40 U/g Hb (p = 0.004) as well as in GL- HD from 3.97 +/- 1.00 to 3.59 +/- 0.87 U/g Hb (p = 0.007). The GSSG-R showed an increase in activity in CRF patients before HD (in GL+ HD to 2.57 +/- 0.76 and in GL- HD to 2.82 +/- 0.98 U/gHb). After dialysis, lower values were observed, particularly in GL+ HD (2.05 +/- 0.59 U/g Hb, p = 0.004). GSH concentrations in the examined group were higher (in GL+ HD 0.0205 +/- 0.008 and in GL- HD 0.0196 +/- 0.008 mmol/g Hb) than in controlled subjects (0.0142 +/- 0.002 mmol/g Hb) and decreased during dialysis treatment (considerably only in GL- HD to 0.0183 +/- 0.007 mmol/g Hb, p = 0.056). Glucose concentrations in GL+ HD were significantly higher compared to GL- HD (p < 0.002). Glucose presence in dialyzing fluid improves the HMP cycle activity as well as glutathione system reactions and determines a better antioxidant status of erythrocytes. It limits hemolysis and improves the hematological parameters in CRF.