Search results for "cysteine"
showing 10 items of 550 documents
Ursodeoxycholic acid protects against secondary biliary cirrhosis in rats by preventing mitochondrial oxidative stress
2004
Ursodeoxycholic acid (UDCA) improves clinical and biochemical indices in primary biliary cirrhosis and prolongs survival free of liver transplantation. Recently, it was suggested that the cytoprotective mechanisms of UDCA may be mediated by protection against oxidative stress, which is involved in the development of cirrhosis induced by chronic cholestasis. The aims of the current study were 1) to identify the mechanisms involved in glutathione depletion, oxidative stress, and mitochondrial impairment during biliary cirrhosis induced by chronic cholestasis in rats; and 2) to determine the mechanisms associated with the protective effects of UDCA against secondary biliary cirrhosis. The find…
Effect of Glutathione on Canine Myocardial Ischaemia Without Reperfusion
1993
Abstract The present study was to evaluate the effect of exogenous glutathione on myocardial damage resulting from permanent (no reperfusion) coronary ligation (3 or 6 h) in anaesthetized dogs. Haemodynamics, infarct size and myocardial glutathione content were determined. Erythrocyte superoxide dismutase (SOD) activity was also determined in coronary venous blood samples. Glutathione was administered by the intraperitoneal route, 100 mg kg−1 as initial dose given 5 min before coronary ligation, and successive doses of 25 mg kg−1 every 40 min throughout the study period. Saline-treated dogs showed myocardial infarction, a decrease in myocardial glutathione content, and a transient increase …
Liver intracellular L-cysteine concentration is maintained after inhibition of the trans-sulfuration pathway by propargylglycine in rats.
1997
To study the fate ofl-cysteine and amino acid homeostasis in liver after the inhibition of the trans-sulfuration pathway, rats were treated with propargylglycine (PPG). At 4 h after the administration of PPG, liver cystathionase (EC4.4.1.1) activity was undetectable,l-cystathionine levels were significantly higher,l-cysteine was unchanged and GSH concentration was significantly lower than values found in livers from control rats injected intraperitoneally with 0.15 M-NaCl. The hepatic levels of amino acids that are intermediates of the urea cycle,l-ornithine,l-citrulline andl-arginine and blood urea were significantly greater. Urea excretion was also higher in PPG-treated rats when compared…
MTHFR C677T allelic variant is not associated to plasma and cerebrospinal fluid homocysteine in amyotrophic lateral sclerosis
2014
Amiotrophic lateral sclerosis (ALS) is a neurological disorder with a multifactorial etiopathogenesis including excitotoxicity, intracellular calcium increase and mitochondrial damage together with oxidative stress and apoptosis. Overall, the relationship between homocysteine (Hcy), motoneuron death and ALS appears to be complex and still under investigation. It has been already shown that Hcy is elevated in plasma and cerebrospinal fluid (CSF) of ALS patients, although mechanisms of hyperhomocysteinemia have not been elucidated yet. MTHFR C677T variant is the most common genetic determinant of increased homocysteinemia, but no studies regarding the effect of this polymorphism in ALS patien…
Biochemical risk indices, including plasma homocysteine, that prospectively predict mortality in older British people: the National Diet and Nutritio…
2010
Predictive power, for total and vascular mortality, of selected indices measured at baseline in the British National Diet and Nutrition Survey (community-living subset) of People Aged 65 Years and Over was tested. Mortality status and its primary and underlying causes were recorded for 1100 (mean age 76·7 (sd7·5) years, 50·2 % females) respondents from the baseline survey in 1994–5 until September 2008. Follow-up data analyses focussed especially on known predictors of vascular disease risk, together with intakes and status indices of selected nutrients known to affect, or to be affected by, these predictors. Total mortality was significantly predicted by hazard ratios of baseline plasma co…
Asymmetric dimethylarginine (ADMA) and hyperhomocysteinemia in patients with acute myocardial infarction
2006
We sought to investigate the association between increased levels of asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, and total plasma homocysteinemia (tHcy) in patients with acute myocardial infarction (AMI).In 138 patients hospitalized for AMI24 h on admission, serum levels of ADMA, its symmetric stereoisomer (SDMA) and tHcy were measured.ADMA was positively associated with SDMA (p0.001) and tHcy (p=0.03) but not with estimated glomerular filtration rates (eGFR, p=0.96), while tHcy strongly correlated with eGFR (p=0.002) and SDMA (p0.001). By multiple linear regression, SDMA but not ADMA was independently associated with tHcy (p=0.005).Our findings sugges…
The aminothiol redox status in haemodialysis patients does not improve with folate therapy.
2008
Patients on haemodialysis suffer from high cardiovascular morbidity and mortality, and oxidative stress may play a role in the pathophysiology of cardiovascular disease in these patients. Hyperhomocysteinemia is common in dialysis patients and may have pro-oxidant effects. Moreover, the redox status of the major plasma aminothiols (homocysteine [Hcy], cysteine and cysteinylglycine) may be regarded as a biomarker of oxidative stress. In the present study, we investigated the aminothiol redox status during a period of homocysteine-lowering therapy with folinic acid.In the first part of the study, 32 stable patients receiving maintenance haemodialysis were compared with 32 reference subjects. …
Blood levels of homocysteine, cysteine, glutathione, folic acid, and vitamin B12 in the acute phase of atherothrombotic stroke.
2009
Blood levels of total homocysteine (tHcy), cysteine (Cys), total and reduced glutathione (tGSH and rGSH), folic acid (FA), and vitamin B(12) (B(12) change during ischemic stroke as accompaniment of the tissue damage. The relationship between these changes remains scantly investigated. We evaluated the variation of these molecules in the 48 h after acute large artery atherothrombotic stroke (LAAS) and searched for the presence of matched variation of them. The study involved 50 subjects affected by acute LAAS and 49 healthy controls. Plasma levels of tHcy and Cys were significantly higher and serum levels of FA and B(12) and plasma levels of rGSH were significantly lower in the patients than…
Protective effect of N-acetylcysteine on ischaemia-induced myocardial damage in canine heart.
1991
The glutathione redox pathway is an important antioxidant system in the myocardium. N-Acetylcysteine is a low molecular weight glutathione precursor that has been used clinically to replenish glutathione stores. The present study was aimed at evaluating the protective effect of N-acetylcysteine on myocardial damage resulting from permanent coronary occlusion (without reperfusion) in anaesthetized dogs. N-Acetylcysteine (150 mg kg−1 i.v.) administered 2 min before occlusion rerduced infarct size in dogs subjected to 24 h ischemia. The infarct size as a percentage of the area at risk was 86.8 ± 3.6% (n = 11) in control (salinetreated) dogs and 68.2 ± 2.4% (n = 7; P < 0.05 vs control) in N-ace…
Increased homocysteine levels correlate with the communication deficit in children with autism spectrum disorder
2015
The clinical significance of high levels of homocysteine in autism spectrum disorder (ASD) is unknown. An experimental study was conducted in order to evaluate the concentration of homocysteine in children with ASD and typically developing children and to analyse any relationships with the severity of core symptoms of ASD and other clinical features (drugs, co-morbidities, gender, age, diet). Core symptoms of autism were evaluated by DSM-IV criteria. Homocysteine, glutathione, methionine, 3-nitrotyrosine were measured in urine. The increase in homocysteine concentration was significantly and directly correlated with the severity of the deficit in communication skills, but was unrelated to d…