Search Results

1 - 10 of 61 items :

  • "oksidativni stres" x
Clear All
Oxidative Stress - Clinical Diagnostic Significance

References Đukić MM. Reaktivne hemijske vrste i oksidativni stres. U: Oksidativni stres - slobodni radikali, prooksidansi i antioksidansi. Urednik. Mirjana Đukić. Izdavač: MONO I MANJANA, Beograd 2008; 15-39. Ćurčić Jovanović M, Đukić M. Azot(II)-oksid u neurotoksičnosti herbicida dipiridilske strukture. U Oksidativni stres - slobodni radikali, prooksidansi i antioksidansi. Urednik. Mirjana Đukić. Izdavač: MONO I MANJANA, Beograd 2008; 217-32. Jelenković A, Jovanović DM, Bošković B

Open access
The Effects of Central Angiotensin II and Its Specific Blockers on Nociception. Possible Interactions with Oxidative Stress Status / Efekti Centralnog Angiotenzina II I Njegovih Specifičnih Blokatora Na Nocicepciju. Moguće Interakcije Sa Statusom Oksidativnog Stresa

Summary

It has already been demonstrated that a complete brain renin-angiotensin system (RAS) exists distinctly separate from the peripheral system and is implicated in complex functions such as memory, emotional responses and pain. Regarding the implications of angiotensin II (the main bioactive peptide of RAS) in pain, although there are many studies in this area of research, most of the results are controversial. Also, it seems that oxidative stress follows angiotensin II infusion, but the role of AT1 vs. AT2 receptors is not well established. In this context, we were interested in studying the effects of central RAS on nociception, through the intracerebroventricular administration of losartan and PD-123177 (antagonists for the AT1/AT2 receptors), as well as an ACE inhibitor (captopril) and also angiotensin II in rats, which were subsequently tested using the hot-plate task, a well known behavioral test for pain perception. We present here the analgesic effect of angiotensin II administration, as shown by in creased latency-time in the hot-plate, as well as a nociceptive effect of angiotensin II blockers like AT1 and AT2 specific antagonists (losartan and PD-123177) and an ACE inhibitor (captopril), as their administration resulted in decreased latency-time. Moreover, we demonstrated a significant correlation between the results of the nociceptive behavioral task and the levels of some main oxidative stress markers. This provides additional evidence for an analgesic effect of Ang II administration, as well as for a nociceptive effect of Ang II blockers. Moreover, a significant correlation between the nociception and angiotensin II-induced oxidative stress is presented.

Open access
Oxidative Stress in Type 2 Diabetes with Iron Deficiency in Asian Indians

Oxidative Stress in Type 2 Diabetes with Iron Deficiency in Asian Indians

A close relationship exists between iron metabolism, diabetes and oxidative stress. Both diabetes and redox active iron are individually known to enhance oxidative stress. However, the role of iron deficiency and oxidative stress in diabetes is not clear; hence, the levels of oxidative stress in type 2 diabetes with and without iron deficiency have been compared. Two groups of 30 patients each with diabetes were selected (one group with iron deficiency and the other group with normal iron levels) and compared with 30 normal healthy controls. The anthropometric parameters, fasting blood sugar, iron profile and oxidative stress parameters (malondialdehyde levels (index of lipid peroxidation) and serum uric acid levels (antioxidant)) were measured. While the diabetes group had significantly increased serum levels of ferritin (an acute phase reactant and antioxidant) in comparison with normal controls (P=0.040), the diabetic group with iron deficiency had decreased serum levels of iron (P =0.000), ferritin (P = 0.000) and uric acid (P = 0.006) and increased levels of malondialdehyde (P = 0.000) in comparison with diabetics without iron deficiency. This study shows an increase in oxidative stress in the diabetic group with iron deficiency together with reduction in antioxidant levels could further promote prooxidant levels and inflammation and in turn result in the development of complications in this high-risk Asian Indian population.

Open access
Inhibition of Central Angiotensin Converting Enzyme Exerts Anxiolytic Effects by Decreasing Brain Oxidative Stress

Inhibition of Central Angiotensin Converting Enzyme Exerts Anxiolytic Effects by Decreasing Brain Oxidative Stress

This study investigated the effects of angiotensin II and captopril intracerebroventricular administration on anxiety status and brain oxidative stress. Elevated plus maze was used in order to asses the anxiety-like behavior, while the biochemical analysis included the determination of some antioxidant defense enzymes like superoxide dismutase and glutathione peroxidase and also a lipid peroxidation product (malondialdehyde). Our results provide additional evidence of angiotensin II induced anxiety-like effects and increased prooxidant status. Moreover, the blockade of angiotensin II, by the administration of an angiotensin converting enzyme inhibitor (captopril) resulted in anxiolytic effects and decreased oxidative stress status. In addition, we found a significant correlation between the time spent by rats in the open arms of the elevated plus maze and oxidative stress markers. This could raise important therapeutic issues regarding the anxiolytic effects of some angiotensin converting enzyme inhibitors used primarily for hypertension, such as captopril. Also, it seems that oxidative stress could play an important part in these actions.

Open access
Effect of Nutritionally Relevant Doses of Long-Chain N-3 Pufa on Lipid Status, Oxidative Stress and Inflammatory Markers in an Average Middle-Aged Serbian Population / Uticaj Preporučenih Doza Dugolančanih N-3 Masnih Kiselina Na Lipidni Status, Oksidativni Stres I Markere Inflamacije Kod Ispitanika Srednjih Godina

Summary

Background: This study investigated the effects of a nutritionally relevant intake of eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids derived from oily fish or a fish oil supplement on selected cardiovascular risk factors in average middle-aged individuals.

Methods: Thirty-three participants were randomized to receive salmon (oily fish) providing 274 mg EPA + 671 mg DHA/day or a commercial fish oil supplement providing 396 mg EPA + 250 mg DHA/day in a cross-over trial over an 8-week period separated by a 6-month washout period. Blood samples were collected before and after each intervention and lipids, inflammatory and oxidative stress parameters were determined.

Results: Plasma levels of EPA, DHA and total n-3 fatty acids significantly increased after both interventions. A decreasing trend in triglycerides was more pronounced with salmon than with the fish oil supplement, but the changes noticed were not significant. Although there were no relevant changes in inflammatory marker concentrations at the end of both interventions, significant negative correlations were noticed between total plasma n-3 fatty acids and soluble intercellular adhesion molecule and Creactive proteinconcenthroughout the whole intervention period (p<0.05). Among the oxidative stress parameters, intervention with salmon showed a prooxidative effect through a superoxide anion increase (p=0.025). A relevant positive correlation was also found between its concentration and total plasma n-3 fatty acids (p<0.05). Other oxidative stress markers were not significantly influenced by the dietary interventions applied.

Conclusion: Following two sets of recommendations for n- 3 fatty acids intake aimed at the general public had only a moderate effect on the selected cardiovascular risk factors in average healthy middle-aged subjects over a short-term period

Open access
Effects of Myosmine on Antioxidative Defence in Rat Liver

Effects of Myosmine on Antioxidative Defence in Rat Liver

Myosmine [3-(1-pyrrolin-2-yl) pyridine] is an alkaloid structurally similar to nicotine, which is known to induce oxidative stress. In this study we investigated the effects of myosmine on enzymatic and non-enzymatic antioxidative defence in rat liver. Wistar rats received a single i.p. injection of 19 mg kg-1 of myosmine and an oral dose of 190 mg kg-1 by gavage. Nicotine was used as a positive control. Through either route of administration, myosmine altered the hepatic function by decreasing the levels of reduced glutathione, superoxide dismutase, and glutathione peroxidase activities on one hand and by increasing malondialdehyde, catalase, and glutathione reductase activity on the other. Compared to control, both routes caused significant lipid peroxidation in the liver and altered hepatic enzymatic and non-enzymatic antioxidative defences. The pro-oxidant effects of myosmine were comparable with those of nicotine.

Open access
Determination of Prooxidant–Antioxidant Balance during Uncomplicated Pregnancy Using a Rapid Assay

Summary

Background: Oxidative stress is thought to be a major contributor to complications during pregnancy, for example preeclampsia. However, reports regarding prooxidant-antioxidant balance in uncomplicated pregnancy are inconsistent. In this study, we aimed to compare the levels of oxidative stress in non-pregnant women with apparently normal pregnant women during the first trimester and at delivery.

Methods: An assay for the determination of prooxidant-antioxidant balance (PAB) was used in this study, in which the prooxidant burden and the antioxidant capacity were measured simultaneously in a single assay. The levels of oxidative stress were determined in 85 non-pregnant and 64 primigravid pregnant women.

Results: Demographic data and biochemical indices did not differ significantly between the groups. Differences between PAB values were significant based on one-way ANOVA analysis (P<0.001). Using a post hoc test, we observed a statistically significant increase in PAB values during the first trimester and last trimester (P<0.001).

Conclusions: Normal pregnancy is associated with a change in the measure of redox status, as assessed by the PAB assay.

Open access
Hydrogen Peroxide in the Troposphere

Vodikov Peroksid U Troposferi

Uloga vodikova peroksida (H2O2) u atmosferskoj kemiji i njegov doprinos u nastanku slobodnih radikala počeli su se proučavati tek posljednjih nekoliko desetljeća. Fotokemijskim reakcijama s ozonom i H2O2 nastaju oksidansi (slobodni radikali) koji mogu oksidirati biomolekule unutar stanica te dovesti do smrti stanica i ozljeda tkiva. Zbog toga se slobodni radikali smatraju uzrokom više od sto bolesti. H2O2 smatra se boljim indikatorom za atmosferski oksidacijski kapacitet od ozona. U atmosferi može biti prisutan u plinovitoj i tekućoj fazi te pokazuje tipične dnevne i sezonske varijacije. Međutim, zbog skupe i složene opreme, mjerenja H2O2 su rijetka i ograničena na samo nekoliko mjesta u svijetu. Mjerenja u slojevima leda na Grenlandu pokazala su da koncentracije H2O2 rastu posljednjih 200 godina. Značajan porast primijećen je upravo posljednjih dvaju desetljeća, a procjene pokazuju da će i dalje rasti zbog smanjene emisije sumporova dioksida. Mjerenja H2O2 u Hrvatskoj do sada još nisu bila provedena te će uporedo s već postojećim dugogodišnjim rezultatima mjerenja ozona i dušikovih oksida dati uvid u stanje i utjecaj na oksidativni stres.

Open access
Association Between Thyroid Hormones, Lipids and Oxidative Stress Markers in Subclinical Hypothyroidism / Povezanost Izme\U Tireoidnih Hormona, Lipida I Markera Oksidativnog Stresa U SubkliniĉKoj Hipotireozi

Summary

Oxidative stress plays a role in the pathogenesis of many chronic diseases. It is recognized in overt hypothyroidism while its existence in subclinical hypothyroidism (SCH) is not well established. The aim of this study was to determine whether there was increased oxidation of lipids and proteins in SCH, and examine their association with lipids and thyroid hormones.

Methods: Male adults (35-59 years) with SCH (n=467) and euthyroid controls (n=190) were studied. Anthropometric measurements, plasma lipids, thyroid stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), total antioxidant capacity (T-AOC), lipid peroxidation products, malondialdehyde (MDA), advanced oxidation protein products (AOPP) and dityrosine concentrations were measured.

Results: Plasma concentrations of MDA were significantly higher (p<0.05) in SCH (8.11±1.39 nmol/mL) compared with euthyroid controls (7.34±1.31 nmol/mL) while AOPP, dityrosine and T-AOC levels were not different. MDA was not associated with TSH (β=-0.019, P=0.759), FT4 (β=-0.062, P=0.323) and FT3 (β=-0.018, P=0.780) in SCH while levels increased with elevated total cholesterol (β=0.229, P=0.001), LDL (β=0.203, P=0.009) and triglycerides (β=0.159, P=0.036) after adjustment for ageand body mass index. T-AOC reduced (β=-0.327, P=0.030) with increased MDA in euthyroid controls and not in SCH (β=-0.068, P=0.349), while levels increased with elevated triglycerides in both groups.

Conclusion: Oxidative stress was increased in subclinical hypothyroidism as evidenced by the elevated lipid peroxidation product, malondialdehyde, while protein oxidation was absent. Thus, reduction of oxidative stress may be beneficial in patients with subclinical hypothyroidism

Open access
Oxidative Stress in Obesity and Metabolic Syndrome in Asian Indians

Oxidative Stress in Obesity and Metabolic Syndrome in Asian Indians

Oxidative stress is associated with the individual components of metabolic syndrome and has been implicated in the development of complications of these metabolic disorders. In this study oxidative stress levels have been compared in obese Indians (a high-risk population for diabetes and cardiovascular disorders) with and without metabolic syndrome. 30 adult normotensive, normoglycemic obese subjects and 35 adults with metabolic syndrome of either sex with BMI >23 kg/m2 were compared with 30 adult, healthy volunteers with BMI <23 kg/m2. Anthropometric parameters, blood pressure, biochemical parameters, hydroperoxides levels and total antioxidant capacity were estimated. The obese groups with and without metabolic syndrome had significantly increased anthropometric parameters like waist circumference and index of central obesity and aqueous phase hydroperoxides when compared with normal controls. The metabolic syndrome group also had significantly increased blood sugar levels, lipid profile and hydroperoxide levels when compared to obese or control groups. There was no alteration in the total antioxidant capacity in any of the groups. The Triglyceride/HDL-Cholesterol ratio (>3), a surrogate marker of insulin resistance, indicates insulin resistance in the metabolic syndrome group. The anthropometric profile, insulin resistance and oxidative stress seen in obesity are further elaborated in metabolic syndrome. Thus, the early identification of high-risk individuals based on anthropometric parameters, lipid profile, insulin resistance and indices of oxidative stress may help to prevent the development of complications of metabolic syndrome.

Open access