THE ROLE of OXIDATIVE STRESS and LIPID PEROXIDATION IN VENTRICULAR REMODELING INDUCED BY TOBACCO SMOKE EXPOSURE AFTER MYOCARDIAL INFARCTION

OBJECTIVE: To evaluate the roles of oxidative stress and lipid peroxidation in the ventricular remodeling that is induced by tobacco smoke exposure after myocardial infarction.METHODS: After induced myocardial infarction, rats were allocated into two groups: C (control, n=25) and ETS (exposed to tobacco smoke, n=24). After 6 months, survivors were submitted to echocardiogram and biochemical analyses.RESULTS: Rats in the ETS group showed higher diastolic (C = 1.52 +/- 0.4 mm(2), ETS = 1.95 +/- 0.4 mm(2); p=0.032) and systolic (C = 1.03 +/- 0.3, ETS = 1.36 +/- 0.4 mm(2)/g; p=0.049) ventricular areas, adjusted for body weight. The fractional area change was smaller in the ETS group (C = 30.3 +/- 10.1 %, ETS = 19.2 +/- 11.1 %; p=0.024) and E/A ratios were higher in ETS animals (C = 2.3 +/- 2.2, ETS = 5.1 +/- 2.5; p=0.037). ETS was also associated with a higher water percentage in the lung (C = 4.8 (4.3-4.8), ETS = 5.5 (5.3-5.6); p=0.013) as well as higher cardiac levels of reduced glutathione (C = 20.7 +/- 7.6 nmol/mg of protein, ETS = 40.7 +/- 12.7 nmol/mg of protein; p=0.037) and oxidized glutathione (C = 0.3 +/- 0.1 nmol/g of protein, ETS = 0.9 +/- 0.3 nmol/g of protein; p=0.008). No differences were observed in lipid hydroperoxide levels (C = 0.4 +/- 0.2 nmol/mg of tissue, ETS = 0.1 +/- 0.1 nmol/mg of tissue; p=0.08).CONCLUSION: In animals exposed to tobacco smoke, oxidative stress is associated with the intensification of ventricular re-remodeling after myocardial infarction.

Histochemical differences in the responses of predominantly fast-twitch glycolytic muscle and slow-twitch oxidative muscle to veratrine

The aim of this study was to investigate if the Na+-channel activating alkaloid veratrine is able to change the oxidative and m-ATPase activities of a fast-twitch glycolytic muscle (EDL, extensor digitorum longus) and slow-twitch oxidative muscle (SOL, soleus) in mice. Oxidative fibers and glycolytic fibers were more sensitive to veratrine than oxidative-glycolytic fibers 15, 30 and 60 min after the i.m. injection of veratrine (10 ng/kg) with both showing an increase in their metabolic activity in both muscles. In EDL, the m-ATPase reaction revealed a significant (p < 0.001) decrease (50%) in the number of type IIB fibers after 30 min while the number of type I fibers increased by 550%. Type I fibers decreased from 34% in control SOL to 17% (50% decrease) in veratrinized muscles, with a 10% decrease in type IIA fibers within 15 min. A third type of fiber appeared in SOL veratrinized muscle, which accounted for 28% of the fibers. Our work gives evidence that the changes in the percentage of the fiber types induced by veratrine may be the result, at least partially, from a direct effect of veratrine on muscle fibers and else from an interaction with the muscle type influencing distinctively the response of a same fiber type. Based on the results obtained in the present study the alterations in EDL may be related to the higher number of Na+ channels present in this muscle whereas those in SOL may involve an action of veratrine on mitochondria. Although it is unlikely that the shift of enzymes activities induced by veratrine involves genotypic expression changes an alternative explanation for the findings cannot be substantiated by the present experimental approach. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Oxidative stress markers and apoptosis in the prostate of diabetic rats and the influence of vitamin C treatment

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Weekend ethanol consumption and high-sucrose diet: resveratrol effects on energy expenditure, substrate oxidation, lipid profile, oxidative stress and hepatic energy metabolism

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of percutaneous transthoracic lung biopsy on oxidative metabolism in sheep

This study aimed to assess the effect of percutaneous transthoracic lung biopsy on the oxidative metabolism of sheep by measuring the oxidative stress markers of superoxide dismutase (SOD), total glutathione (GSH-t), peroxidase (GSH-Px) and thiobarbituric acid reactive substances (TBARS) in the red cells of these animals. Blood samples were collected from 20 clinically healthy sheep prior to, and 30 min after, percutaneous transthoracic lung biopsy. After biopsy, there was a significant decrease (p < 0.05) in SOD and GSH-Px activity, with no significant change (p ≥ 0.05) in GSH-t and TBARS concentrations. These results showed that percutaneous transthoracic lung biopsy did not significantly affect the oxidative metabolism of sheep 30 min after the procedure, which may be used widely in this species without causing serious tissue damage. © 2012. The Authors.

Comparison of oxidative stress in ASA physical status I patients scheduled for minimally invasive surgery under balanced or intravenous anesthesia

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cardiac Energy Metabolism and Oxidative Stress Biomarkers in Diabetic Rat Treated with Resveratrol

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sex hormones change visceral pigmentation in Eupemphix nattereri (Anura): effects in testicular melanocytes and hepatic melanomacrophages

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Low intensity physical exercise attenuates cardiac remodeling and myocardial oxidative stress and dysfunction in diabetic rats

We evaluated the effects of a low intensity aerobic exercise protocol on cardiac remodeling and myocardial function in diabetic rats. Wistar rats were assigned into four groups: sedentary control (C-Sed), exercised control (C-Ex), sedentary diabetes (DM-Sed), and exercised diabetes (DM-Ex). Diabetes was induced by intraperitoneal injection of streptozotocin. Rats exercised for 9 weeks in treadmill at 11 m/min, 18 min/day. Myocardial function was evaluated in left ventricular (LV) papillary muscles and oxidative stress in LV tissue. Statistical analysis was given by ANOVA or Kruskal-Wallis. Echocardiogram showed diabetic groups with higher LV diastolic diameter-to-body weight ratio and lower posterior wall shortening velocity than controls. Left atrium diameter was lower in DM-Ex than DM-Sed (C-Sed: 5.73 ± 0.49; C-Ex: 5.67 ± 0.53; DM-Sed: 6.41 ± 0.54; DM-Ex: 5.81 ± 0.50 mm; P < 0.05 DM-Sed vs C-Sed and DM-Ex). Papillary muscle function was depressed in DM-Sed compared to C-Sed. Exercise attenuated this change in DM-Ex. Lipid hydroperoxide concentration was higher in DM-Sed than C-Sed and DM-Ex. Catalase and superoxide dismutase activities were lower in diabetics than controls and higher in DM-Ex than DM-Sed. Glutathione peroxidase activity was lower in DM-Sed than C-Sed and DM-Ex. Conclusion. Low intensity exercise attenuates left atrium dilation and myocardial oxidative stress and dysfunction in type 1 diabetic rats.

Changes in the oxidative stress biomarkers in liver of streptozotocin-diabetic rats treated with combretum lanceolatum flowers extract

Aims: The study investigated the in vivo antioxidant activity and the in vitro radical scavenging capacity of the Combretum lanceolatum Pohl (Combretaceae) flowers ethanolic extract (ClEtOH) in streptozotocin-diabetic rats. Place and Duration of Study: Department of Chemistry, Federal University of Mato Grosso, Cuiabá, Brazil; between February 2012 and December 2012. Methodology: Male Wistar rats were divided into four groups: Normal rats treated with water/vehicle (N); diabetic rats treated with water (DC); diabetic rats treated with 250 mg/kg (DT250) or with 500mg/kg (DT500) of ClEtOH. After 21 days of treatment, liver samples were used for the analysis of the oxidative stress biomarkers and activity of antioxidant enzymes. In vitro radical scavenger capacity was investigated by the following methods: DPPH radical scavenging, ABTS radical cation decolorization and crocin bleaching assays. Results: Significant oxidative stress was observed in liver of DC, since the malondialdehyde (MDA, biomarker of lipoperoxidation) levels were increased in comparison with N. Increased activities of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were also observed in DC, which could represent a compensatory mechanism against oxidative stress. Glutathione (GSH) levels were lower and similar between N and DC. The MDA levels were significantly decreased in liver of rats from DT250 and DT500, reaching levels similar those of N, suggesting that ClEtOH prevented lipoperoxidation. The treatment of diabetic rats with ClEtOH also increased the GSH levels, as well as increased the GSH-Px activity, and did not change the SOD activity. The results of in vitro radical scavenging capacity indicated that ClEtOH is highly active. Conclusion: These findings indicate that ClEtOH has antioxidant properties in liver of diabetic rats, decreasing lipoperoxidation and increasing the endogenous antioxidant responses. Both the antihyperglycemic effect and the capacity to scavenge free radicals may be related to the antioxidant activity of ClEtOH in diabetes.