Fatty acid profile in erythrocyte membranes and plasma phospholipids affects significantly the extent of inflammatory response to coronary stent implantation.

In coronary heart disease, the treatment of significant stenosis by percutaneous coronary intervention (PCI) with stent implantation elicits local and systemic inflammatory responses. This study was aimed at evaluation of the dynamics of inflammatory response and elucidation of the relationship between the fatty acid profile of red blood cell (RBC) membranes or plasma phospholipids and inflammation after PCI. High-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), serum amyloid A (SAA), malondialdehyde (MDA) and the fatty acid profiles were determined in patients with advanced coronary artery disease undergoing PCI before, 24 h and 48 h after drug-eluting stent implantation (n=36). Patients after PCI exhibited a significant increase in studied markers (hsCRP, IL-6, SAA, MDA). Many significant associations were found between the increase of IL-6, resp. SAA and the amounts of n-6 polyunsaturated fatty acids (namely linoleic, dihomo-gamma-linolenic, docosatetraenoic and docosapentaenoic acid), resp. saturated fatty acids (pentadecanoic, stearic, nonadecanoic) in erythrocyte membranes. The magnitude of the inflammatory response to PCI is related to erythrocyte membrane fatty acid profile, which seems to be a better potential predictor of elevation of inflammatory markers after PCI than plasma phospholipids.

Long-term stability of parameters of antioxidant status in human serum.

The antioxidant status of serum or plasma can be determined using several commercially available assays. Here, four different assays, total antioxidant status (TAS), its second-generation assay (TAS2), biological antioxidant potential (BAP), and enzymatic assay using horseradish peroxidase (EAOC), were applied on human serum samples to test the temperature stability of antioxidants, upon storage of serum for 12 months. The two or three most commonly used temperatures for storage, that is, - 20, - 70 (or - 80), and - 196°C, were selected. The general conclusion is that all assays were stable at the temperatures tested. In addition, there were almost no statistically significant differences between the samples stored at different temperatures. Only the rank order of the EAOC assay was not very good in samples stored at - 20°C. Also three components contributing to the total antioxidant capacity, uric acid, creatinine and bilirubin, showed no statistically significant differences between the temperatures. Therefore, storage at - 20°C is sufficient to maintain a proper assay outcome of most of the total antioxidant assays, although storage at - 70/80°C is to be preferred for longer storage times.

Oxidative stress and metabolic syndrome in obese adults with and without controlled diet restriction.

BACKGROUND: Metabolic syndrome (MetS) represents a collection of markers associated with cardiovascular morbidity and mortality. Due to its high prevalence and steady increase of the occurrence, prevention or management of MetS is of paramount importance. The aim of our study was to evaluate MetS occurrence and extent of oxidative stress by comparing obese adults after diet optimization with untreated controls. MATERIAL AND METHODS: Oxidative stress markers (total amount of free radicals, malondialdehyde, allantoin, alpha1-antiproteinase, GSSG/GSH ratio), total antioxidant capacity and lipid standardized alpha-tocopherol were determined in 40 obese people and 48 healthy controls. The obese people were divided into two group A: obese with restricted energy intake with lowered dietary carbohydrates (n=20) and group B: with the same grade of obesity but without following dietary recommendations (n=20). RESULTS: Group A exhibited lower oxidative stress markers than group B; free radicals (5.18+/-1.68 vs 8.43+/-3.66 mmol/l, p<0.01), GSSG/GSH ratio (11.74+/-5.01 vs 15.38+/-5.93%, p<0.05) and higher antioxidants: lipid standardized alpha-tocopherol (3.70+/-0.51 vs 3.35+/-0.60, p<0.05) and ceruloplasmin (0.24+/-0.08 vs 0.21+/-0.03 g/l, p<0.05), in the course of same grade of obesity. Furthermore MetS occurrence was found significantly lower was in group A. CONCLUSION: The energy intake restriction by 2000 kJ, mainly due to carbohydrate limitations, was associated with decreased oxidative stress and simultaneously increased lipid-standardized alpha-tocopherol and ceruloplasmin in obese people. These changes correlated with diminished MetS occurrence by about 50% (Tab. 3, Ref. 32). Full Text (Free, PDF) www.bmj.sk.

Evaluation of oxidative status in acetaminophen treated rat hepatocytes in culture.

The present study describes the estimation of acetaminophen (AAP) toxicity in cultured rat hepatocytes. We used different concentrations of AAP - 1, 2.5, 5, 10 and 20 mM, to test influence of AAP on cellular viability, functional capacity and oxidative status at given time intervals. WST 1 test showed decrease of dehydrogenase activity in 5, 10 and 20 mM AAP to 75 % of control values after 1 hour of incubation. At 12 h of treatment, all AAP concentrations decreased WST-1 signal; no enzyme activity was found since 18 h in cells treated with 20 mM AAP according to LDH leakage test performed at 24 h of incubation. Functional capacity was tested by albumin assay where the decrease was strictly related to AAP dose. Intracellular oxidative status was assessed by analysis of GSH/GSSG levels and time course of ROS production and glutathione reductase (GR) activity. Increased ROS production was found already after 3 h of incubation in 2.5, 5, 10 and 20 mM AAP, respectively. The highest ROS production was measured after 12 h treatment. GR activity was decreased already after 3 h of incubation and remained also decreased in cells treated with 2.5, 5, 10 and 20 mM AAP during further incubation.

Protective effect of S-adenosylmethionine against galactosamine-induced injury of rat hepatocytes in primary culture.

The protective effect of S-adenosylmethionine (SAMe) on D-galactosamine (GalN)-induced damage to rat hepatocytes was tested in primary cultures. SAMe at concentrations of 50 and 1000 mg/l significantly reduced lactate dehydrogenase release from cells injured by 40 mM GalN after 24 h of incubation. There were no significant changes in urea production after 24 h among tested groups, including control hepatocytes. Exposure of hepatocytes to GalN leads to 3.5-fold decrease in urea synthesis after 48 h in comparison with control cell cultures. Addition of the highest dose of SAMe (1000 mg/l) into the culture media attenuated this decrease by 180 %. None of the tested doses of SAMe (5, 25, 50 and 1000 mg/l) affected considerably the reduced activity of mitochondrial dehydrogenases. The content of reduced and oxidized glutathione in GalN-exposed cells was diminished to 1.5 % and 16 %, respectively, of the control values after 24 h. Using only the highest concentration SAMe increased significantly these contents. SAMe had no effect on dramatically decreased albumin synthesis. These findings indicate beneficial effect of SAMe, especially of the highest concentration, on GalN-induced toxicity to rat hepatocytes in primary culture. This action of SAMe seems to be associated with reduction of plasma membrane damage and increased synthesis of glutathione.

Antioxidant vitamin levels do not exhibit negative correlation with the extent of acute myocardial infarction.

Serum levels of vitamin E (VE), beta-carotene (BC) and vitamin C (VC) were determined in 50 patients with the first acute myocardial infarction (AMI) before starting thrombolytical treatment. VE and BC were determined by HPLC, VC spectrophotometrically. The reperfused patients were divided according to vitamin concentrations into four groups. The lowest quartile was compared with the rest of the studied population (VE: group with high (H)>15.6 microM>group with low (L), BC: H>0.07 microM>L, VC: H>25 microM>L) in the following parameters: extent of myocardial damage (area under the curves of troponin I, CK-MB during 48 h), arrhythmia and congestive heart failure occurrence, size of ejection fraction, positivity of ventricular late potentials. No significant differences between groups H and L for either VE, BC or VC were found (P 0.05). As no correlation between serum concentrations of vitamins E, C and beta-carotene and the extent and clinical course of AMI was found, the actual vitamin concentrations may be important for prevention of ischemic heart a disease, but they do not play a decisive role in the acute phase of myocardial infarction in humans.

Antioxidant vitamin pool in senior population.

AIM: To compare plasma concentration of alpha-tocopherol and ascorbic acid in healthy seniors (age over 65 years), senior patients with either diabetes mellitus, acute myocardial infarction or dyslipidemia and recommended values of these vitamins. METHODS: Studied groups included 30 patients with diabetes mellitus (DM); 30 patients 1 - 2 weeks after acute myocardial infarction (AMI); 11 patients with lipid metabolism disorder (LD, total cholesterol > 6.2 mM); and control group of 27 healthy persons. RESULTS: Concentration of alpha-tocopherol in DM group was 14.6 +/- 5.3 microM, in AMI group 13.7 +/- 5.6 microM, in LD group 15.9 +/- 5.6 microM and in control group 12.9 +/- 4.1 microM. No statistically significant differences were found. However, comparison of determined values with levels recommended for prevention revealed remarkable low plasma concentration of alpha-tocopherol in the Czech population. Plasma concentration of ascorbic acid in DM group was 47.07 +/- 22.80 microM, in AMI group 33.15 +/- 12.81 microM, in LD group 45.59 +/- 23.02 microM and in control group 43.28 +/- 26.57 microM. No statistically significant differences were found between the controls and individual groups of patients. Plasma concentrations of vitamin C reached the recommended value in all cases except the AMI group, where it was significantly lower. CONCLUSION: Seniors in the Czech population were proved to be significantly short of alpha-tocopherol, minor shortage of vitamin C was found only in group of patients with myocardial infarction.

Antioxidant vitamin levels and glutathione peroxidase activity during ischemia/reperfusion in myocardial infarction.

The consequences of increased oxidative stress, measured as the level of malondialdehyde (MDA) during ischemia/reperfusion, were studied in 48 patients in the acute phase of myocardial infarction (AMI) and a control group (21 blood donors). The serum levels of alpha-tocopherol and beta-carotene were followed. Immediately after the treatment onset the level of alpha-tocopherol started to decrease, reaching a plateau after 24 h. The consumption of beta-carotene was delayed by 90 min. Steady decline was detected during the whole time interval studied (48 h). Glutathione peroxidase (GPx) activity, as a representative of antioxidant enzymes, was estimated in whole blood. The influx of oxygenated blood was accompanied by a stimulation of GPx activity, which reached its maximum at the time of completed reperfusion. When comparing the AMI patients with the control group, the levels of MDA were found significantly increased, which indicates that oxidative stress is already increased during ischemia. Lower antioxidant levels found in the patients might either already be the result of vitamin consumption during ischemia or be a manifestation of their susceptibility to AMI. Monitored consumption of alpha-tocopherol and beta-carotene during reperfusion indicated that in the case of patients, whose level of antioxidant vitamins is below the threshold limit, a further substantial decrease of antioxidant vitamins during reperfusion could enhance the oxidative damage of the myocardium.

Selective antioxidant enzymes during ischemia/reperfusion in myocardial infarction.

The study of ischemia/reperfusion injury included 25 patients in the acute phase of myocardial infarction (19 perfused, 6 remained non-reperfused as evaluated according to the time course of creatine kinase and CK-MB isoenzyme activity) and a control group (21 blood donors). Plasma level of malondialdehyde was followed as a marker of oxidative stress. Shortly after reperfusion (within 90 min), a transient increase of malondialdehyde concentration was detected. The return to the baseline level was achieved 6 h after the onset of therapy. The activity of a free radical scavenger enzyme, plasma glutathione peroxidase (GPx), reached its maximum 90 min after the onset of treatment and returned to the initial value after 18 h. The specificity of the GPx response was confirmed by comparing with both non-reperfused patients and the control group, where no significant increase was detected. The erythrocyte Cu,Zn-superoxide dismutase (SOD) did not exhibit significant changes during the interval studied in perfused patients, probably due to the stability of erythrocyte metabolism. In non-reperfused patients, a decrease of SOD was found during prolonged hypoxia. These results help to elucidate the mechanisms of fast activation of plasma antioxidant system during the reperfusion after myocardial infarction.