Effect of octreotide on oxidative stress in the erythrocyte and kidney tissue in adriamycin-induced experimental nephrotic syndrome model / Efeito do octreotide no estresse oxidativo em eritrócitos e no tecido renal no modelo de síndrome nefrótica experimental induzida por adriamicina

Abstract Introduction: Nephrotic syndrome (NS) is one of the reasons of end-stage kidney disease, and elucidating the pathogenesis and offer new treatment options is important. Oxidative stress might trigger pathogenesis systemically or isolated in the kidneys. Octreotide (OCT) has beneficial antioxidant effects. We aimed to investigate the source of oxidative stress and the effect of OCT on experimental NS model. Methods: Twenty-four non-uremic Wistar albino rats were divided into 3 groups. Control group, 2 mL saline intramuscular (im); NS group, adriamycin 5 mg/kg intravenous (iv); NS treatment group, adriamycin 5 mg/kg (iv) and OCT 200 mcg/kg (im) were administered at baseline (Day 0). At the end of 21 days, creatinine and protein levels were measured in 24-hour urine samples. Erythrocyte and renal catalase (CAT) and thiobarbituric acid reactive substance (TBARS) were measured. Renal histology was also evaluated. Results: There was no significant difference among the 3 groups in terms of CAT and TBARS in erythrocytes. Renal CAT level was lowest in NS group, and significantly lower than the control group. In treatment group, CAT level significantly increased compared with NS group. In terms of renal histology, tubular and interstitial evaluations were similar in all groups. Glomerular score was significantly higher in NS group compared with control group and it was significantly decreased in treatment group compared to NS group. Conclusions: Oxidative stress in NS might be due to the decrease in antioxidant protection mechanism in kidney. Octreotide improves antioxidant levels and histology in renal tissue and might be a treatment option.

Resumo Introdução: Síndrome nefrótica (SN) é uma das causas de doença renal em estágio terminal. É importante elucidar a patogênese e oferecer novas opções de tratamento. Estresse oxidativo pode desencadear a patogênese sistemicamente ou isoladamente nos rins. O octreotide (OCT) tem efeitos antioxidantes benéficos. Nosso objetivo foi investigar a fonte de estresse oxidativo e efeito do OCT no modelo experimental de SN. Métodos: Dividimos 24 ratos albinos Wistar não urêmicos em 3 grupos. Grupo controle, 2 mL de solução salina intramuscular (im); grupo SN, adriamicina 5 mg/kg intravenosa (iv); grupo tratamento SN, adriamicina 5 mg/kg (iv) e OCT 200 mcg/kg (im) foram administrados no início do estudo (Dia 0). Aos 21 dias, mediram-se os níveis de creatinina e proteína em amostras de urina de 24 horas. Mediu-se a catalase (CAT) eritrocitária e renal e a substância reativa ao ácido tiobarbitúrico (TBARS). Avaliou-se também histologia renal. Resultados: Não houve diferença significativa entre os três grupos em termos de CAT e TBARS em eritrócitos. O nível de CAT renal foi menor no grupo SN e significativamente menor que no grupo controle. No grupo tratamento, o nível de CAT aumentou significativamente em comparação com o grupo SN. Quanto à histologia renal, as avaliações tubular e intersticial foram semelhantes em todos os grupos. O escore glomerular foi significativamente maior no grupo SN em comparação com o grupo controle e diminuiu significativamente no grupo de tratamento em comparação com o grupo SN. Conclusões: Estresse oxidativo na SN pode ser devido à diminuição do mecanismo de proteção antioxidante nos rins. O octreotide melhora níveis de antioxidantes e histologia do tecido renal e pode ser uma opção de tratamento.

High-intensity exercise-induced oxidative stress in sedentary pre-pubertal & post-pubertal boys: A comparative study

Background & objectives: High-intensity exercise results in oxidative stress in adult population. Impact of pubertal attainment on high-intensity exercise-induced oxidative stress in sedentary paediatric population has not been investigated in detail. The present study was conducted to investigate the extent of high-intensity exercise-induced oxidative stress in sedentary pre- and post-pubertal boys through estimation of serum thiobarbituric acid reactive substances (TBARS), total thiol content and activities of superoxide dismutase (SOD) and catalase (CAT). Methods: Sixty four sedentary pre-pubertal (n=32, age = 10.21�67 yr) and post-pubertal (n=32, age = 15.58�47 yr) boys performed incremental treadmill running exercise at 80 per cent of the age predicted maximum heart rate till volitional exhaustion. Blood sample (5 ml) was drawn from each individual before and after the exercise for estimation of oxidative stress markers. Results: Pre-exercise SOD activity and total thiol level showed significant positive relationship with age and were significantly higher in post-pubertal boys. Serum TBARS level, SOD and CAT activities increased while total thiol content decreased in both the groups following exercise. Post-exercise percentage change in TBARS, SOD activity and total thiol level was significantly higher in post-pubertal boys, and these variables had significant positive relationship with age. No significant intergroup variations were noted in CAT activity before or after exercise. Interpretation & conclusions: Extent of post-exercise oxidative stress increased significantly with attainment of puberty. However, baseline and post-exercise antioxidation status also increased significantly as a function of age with pubertal maturation allowing the post-pubertal boys to counter relatively higher oxidative stress more efficiently than their pre-pubertal counterparts. Post-exercise upregulation in CAT activity might not be influenced by age or pubertal maturation in this age group.

Oxidative Stress in the Heart of Rats Infected with Trypanosoma evansi

This study was conducted to investigate the occurrence of oxidative stress in the heart tissue of rats infected with Trypanosoma evansi. Rats were divided into 2 groups (A and B) with 12 animals each, and further subdivided into 4 subgroups (A1 and A2, 6 animals/each; and B1 and B2, 6 animals/each). Animals in the groups B1 and B2 were subcutaneously inoculated with T. evansi. Thiobarbituric acid reactive substances (TBARS), superoxide dismutase activity (SOD), glutathione S-transferase activity (GST), reduced glutathione activity (GSH), and non-protein thiols (NPSH) in the heart tissue were evaluated. At day 5 and 15 post-infection (PI), an increase in the TBARS levels and a decrease in the SOD activity (P<0.05) were observed. GSH and GST activities were decreased in infected animals at day 15 PI (P<0.05). Considering the proper functioning of the heart, it is possible that the changes in the activity of these enzymes involved in the oxidative stress may be related, at least in part, in the pathophysiology of rats infected with T. evansi.

Effects of the Exposure to Polycyclic Aromatic Hydrocarbons or Toluene on Thiobarbituric Acid Reactive Substance Level in Elementary School Children and the Elderly in a Rural Area / 예방의학회지

OBJECTIVES: Polycyclic aromatic hydrocarbons (PAH) and toluene have been reported to induce reactive oxygen species and oxidative stress. This study was performed to investigate the effects of low level exposure to PAHs or toluene on the lipid peroxidation level in elementary school children and the elderly in a rural area. METHODS: Forty seven elementary school children and 40 elderly people who were living in a rural area and not occupationally exposed to PAH or toluene were the subjects of this study. Information about active or passive smoking and diet was obtained using a self-administered questionnaire. The urinary 1-hydroxypyrene (1-OHP), 2-naphthol, hippuric acid and thiobarbituric acid reactive substance (TBARS) concentrations were measured, and these values were corrected with the urinary creatinine concentration. RESULTS: In school children, the geometric means of the urinary 1-OHP, 2-naphthol, hippuric acid and TBARS levels were 0.02 ymol/mol creatinine, 0.47 micron mol/mol creatinine, 0.14 g/g creatinine and 0.95 micron mol/g creatinine, respectively. Those values for the elderly were 0.07 micron mol/mol creatinine, 1.87 micron mol/mol creatinine, 0.11 g/g creatinine and 1.18 micron mol/g creatinine, respectively. The mean levels of urinary 1-OHP, 2-naphthol and TBARS were significantly higher in the elderly subjects than in the children. The urinary TBARS level was not correlated with the urinary 1-OHP, 2-naphthol and hippuric acid, but they were correlated with the age of the subjects. CONCLSIONS: These results suggest that low level inhalation exposure to PAH or toluene does not markedly increase lipid peroxidation, and age is a significant determinant of lipid peroxidation.

Plasma, Tissue Thiobarbituric Acid Reactive Substance and Lymphocyte Oxidative DNA Damage in Mouse Fed Gamma Irradiated Diet

Food irradiation has been steadily increasing in many countries in line with increasing international trade and concerns about naturally occurring harmful contaminants in food. Although irradiation provides an excellent safeguard for the consumer by destroying almost 100% of harmful bacteria, it is necessary to ensure the safety of irradiated foods. This study was performed to investigate the effect of an irradiated diet on lipid peroxidation in the plasma, liver, small intestinal mucosa, and lymphocyte DNA damage in mice. Eight-week old ICR mice were assigned to two groups to receive either non-irradiated or irradiated (10 kGy) diets containing 20.38% fish powder and 6.06% sesame seeds for 4 weeks. The resulting changes in the degrees of lipid peroxidation were evaluated based on the level of plasma and liver thiobarbituric acid reactive substance (TBARS), transmission electron micrograph of jejunal mucosa, and free radical-induced oxidative DNA damage in lymphocytes, as measured by alkaline comet assay (single cell gel electrophoresis). The peroxide values of the gamma irradiated diet were measured every week, and the sample for comet assay was taken at the end of the four week experimental period. There was no significant difference in food efficiency ratio between the two groups. The peroxide values of the diet were immediately increased to 35.5% after gamma irradiation and kept on increasing during storage. After 4 weeks, no differences in tissue or plasma TBARS value were observed between the two groups, but epithelial cells of jejumum showed osmiophillic laminated membranous structures, considered as myelin figures,. The oxidative DNA damage expressed as tail moment (TM) increased 30% in the blood lymphocytes of the mice fed the irradiated diet. In conclusion, the comet assay sensitively detected differences in lymphocyte DNA damage after feeding with the irradiated diet for 4 weeks. However, in order to ensure the safety of irradiated foods, it would be more useful to conduct a long-term feeding regimen using an irradiated diet and examine the level of lipid peroxidation and the state of oxidative stress in a greater range of organs.