Nitrotyrosine formation and heme oxygenase-1 expression in endotoxemic cirrhotic rats

Background. Endotoxemia increases hepatic toxicity and mortality in cirrhosis. Because the mechanism of augmented hepatotoxicity in endotoxemic cirrhotic rats is still unclear, we wanted to investigate whether oxidative and nitrosative stress play a causative role in lipopolysaccharide (LPS)-treated cirrhotic rats

Spectral effect: each population must have its own normal midnight salivary cortisol reference values determined

Introduction: The mesurement of midnight salivary cortisol provides the most sensitive method for screening of Cushing's sendrome. However the clinical significance of spectral error is the requirement for determination of normal reference values in each population for each test, which will be used as the diagnostic method. Salivary cortisol levels may be affected by individual factors such as nutrition, sleep, medication, activity, and gender. Being a non-invasive method, midnight salivary cortisol (MSC) has been used as a valuable indicator of free plasma cortisol

I405V and TaqIB polymorphisms of the cholesteryl ester transfer protein and their relation to serum lipid and lipoprotein levels in a Turkish population

Cholesteryl ester transfer protein (CETP) plays a central role in high-density lipoprotein (HDL) metabolism. Genetic polymorphisms of the CETP gene can influence levels of serum lipoproteins. It has been reported that mean HDL-cholesterol (HDL-C) concentrations are low in Turkish population. Thus, we investigated the frequencies of the common I405V and 7aqIB polymorphisms of the CETP gene and their relation to serum lipid and lipoprotein levels in a Turkish population. The variant allele frequencies of 1405V and TaqIB polymorphisms of the CETP gene were found to be 0.38 and 0.46, respectively and similar to some of the European populations. Subjects for the VV genotype of 1405V polymorphism had higher HDL-C levels than did II subjects. The covariance analysis showed that gender and triglyceride (TG) levels have an effect on the association of HDL-C and 1405V polymorphism. In conclusion, our results indicate that 1405V polymorphism may affect the HDL-C levels in Turkish population. The association of this polymorphism and HDL-C levels could be modified by other factors, such as gender and TG levels. Copyright (C) 2009 John Wiley & Sons, Ltd

Effect of taurine treatment on pro-oxidant-antioxidant balance in livers and brains of old rats

The effect of taurine treatment on antioxidant defense in liver and brain tissues of old rats was investigated. Endogenous malondialdehyde (MDA) and diene conjugate (DC), ascorbic acid (AA)-and NADPH-induced lipid peroxide levels as well as non-enzymatic (glutathione - GSH, vitamin E and vitamin C) and enzymatic antioxidants (superoxide dismutase, glutathione peroxidase and glutathione transferase) were determined in livers and brains of young (5 months), old (22 months), and taurine-treated old rats. Taurine (2%, w/v; in drinking water) was administered to old rats for 6 weeks. Taurine levels decreased in the liver and brain of old rats compared to young rats. MDA and DC levels increased, GSH levels decreased, but induced lipid peroxidation remained unchanged in livers of aged rats. Oxidative stress parameters did not change in brains of aged rats. Taurine treatment resulted in significant increases in taurine levels, decreases in MDA and DC levels and increases in GSH levels in livers of old rats. Taurine treatment also increased brain taurine levels. However, no significant changes were detected in lipid peroxidation and antioxidant system in brains of old rats following taurine treatment. Accordingly, in old rats the liver seems more susceptible to age-related lipid peroxidation increases and taurine level changes than the brain. Thus, taurine supplementation seems to be useful for decreasing hepatic oxidative stress in aging

Single nucleotide polymorphisms in base-excision repair genes hOGG1, APE1 and XRCC1 do not alter risk of Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with a poorly understood etiology. There is considerable evidence that oxidative stress occurs in AD and increased DNA damage has been found in brain tissues and leukocytes of AD patients. Base excision repair (BER) is the major pathway responsible for removing oxidative DNA damage. Polymorphisms in DNA-repair genes have been associated with the increased risk of several age-related disorders including various types of cancer and could also be related to the etiology of AD. We conducted a case-control study including 91 patients with AD and age- and sex-matched 93 control subjects to examine the role of single nucleotide polymorphisms of BER genes, hOGG1 (Ser326Cys), APE1 (Asp148Glu) and XRCC1 (Arg280His and Arg399Gln) as a risk factor for AD. The frequencies of the hOGG1-Ser326Cys, APE1-Asp148Glu and XRCC1-Arg280His and XRCC1-Arg399Gln variant alleles in our control group were 0.23, 0.31, 0.10 and 0.33, respectively. No significant association was observed between the variant alleles of hOGG1-Ser326Cys (OR = 1.32, 95% CI = 0.83-2.11), APE1-Asp148Glu (OR = 1.08, 95% CI = 0.70-1.68), XRCC1-Arg280His (OR = 0.53, 95% CI = 0.24-1.14) and XRCC1-Arg399Gln (OR = 1.05, 95% CI = 0.68-1.63) and AD. Our results suggest that the polymorphic variants of these BER genes are not independent risk factors for AD. © 2008 Elsevier Ireland Ltd. All rights reserved

Effects of carnosine on prooxidant-antioxidant status in heart tissue, plasma and erythrocytes of rats with isoproterenol-induced myocardial infarction

Rats were injected with isoproterenol (ISO; 110 mg/kg, ip, 2 doses, 24 h interval) to induce acute myocardial infarction (AMI) and were sacrificed 6 and 24 h after the last ISO injection. The heart tissue, plasma and erythrocytes of these rats were evaluated for cardiac markers and oxidative stress parameters. Levels of cardiac troponin T (cTnT) and the activities of creatine kinase (CK), lactate dehydrogenase (LDH), and aspartate aminotransferase (AST) in plasma were increased 6 and 24 h after ISO treatment. The levels of malondialdehyde (MDA), diene conjugate (DC), and protein carbonyl (PC) were increased in heart tissue and plasma, while levels of erythrocyte MDA and glutathione (GSH) and plasma ferric reducing antioxidant power (FRAP) were also increased. However, GSH levels and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) decreased in heart tissue of rats with AMI. We also investigated the effects of carnosine (CAR) treatment on these parameters 24 h after the last ISO injection. CAR (250 mg/kg/day; ip) treatments were carried out either 10 days before ISO injection or 2 days concomitant with ISO. Pretreatment with CAR decreased plasma LDH and AST activities and ameliorated cardiac histopathological changes in ISO-treated rats. Cardiac MDA, DC and PC levels decreased, but GSH levels and SOD and GSH-Px activities increased. However, the increases in plasma MDA and PC levels as well as erythrocyte H2O2-induced MDA and GSH levels did not change due to CAR pretreatment. In conclusion, our findings indicate that CAR pretreatment may have protective effects on ISO-induced cardiac toxicity by decreasing oxidative stress. (C) 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved