Search results for "Free Radical"
showing 10 items of 263 documents
Attenuation by oralN-acetylcysteine of bleomycin-induced lung injury in rats
2001
Antioxidant therapy may be useful in diseases with impaired oxidant-antioxidant balance such as pulmonary fibrosis. This study examines the effect ofN-acetylcysteine (NAC) on bleomycin-induced lung fibrosis in rats.NAC (3 mmol·kg−1; oral) was given daily from 1 week prior to a single intratracheal instillation of bleomycin (2.5 U·kg−1) or saline, until 14 days postinstillation.NAC partially decreased the augmented collagen deposition in bleomycin-exposed rats (hydroxyproline content was 4,354±386 and 3,416±326 µg·lung−1in vehicle-treated and NAC-treated rats, respectively; p<0.05). The histological assessment using a semiquantitative score showed less collagen deposition and inflammatory…
The effects of nitric oxide on striatal serotoninergic transmission involve multiple targets: an in vivo microdialysis study in the awake rat
2004
Abstract The role of endogenous nitric oxide (NO) in N -methyl- d -aspartate (NMDA)-induced modulation of serotonin (5-HT) release in the striatum of freely moving rats has been studied using microdialysis technique. NMDA-induced increase in 5-HT release was significantly inhibited by selective nitric oxide synthase (nNOS) inhibitor S -methylthiocitrulline (S-Me-TC), ONOO − scavenger l -cysteine ( l -cys), and guanylate cyclase (GC) inhibitor 1 H [1,2,4]oxadiazolo[4,3- a ]quinoxalin-1-one (ODQ). These data suggest that modulation of 5-HT levels is linked to the formation of NO produced by NMDA receptor activation and that endogenously produced NO increases 5-HT concentrations both by stimul…
Pneumocyte Apoptosis Induction during Cardiopulmonary Bypass: Effective Prevention by Radical Scavenging UsingN-Acetylcysteine
2007
Cardiopulmonary bypass (CPB) and cardioplegic arrest are associated with pulmonary dysfunction. We sought to investigate whether pulmonary ischemia/reperfusion during standard CPB and cardioplegic arrest is associated with reactive oxygen species (ROS)-mediated pulmonary tissue injury and pneumocyte apoptosis induction, and whether ROS scavenging using N-acetylcysteine (NAC) attenuates these alterations. Twelve pigs (41 +/- 8 kg) were randomized to receive either NAC (100 mg/kg prior to CPB; n = 7) or placebo (n = 5) and subjected to CPB and 60 min of cold (4 degrees C) crystalloid cardioplegic arrest. We collected lung biopsies prior to CPB, at 60 min CPB, as well as at 30, 60, and 120 min…
Effectiveness of oral N -acetylcysteine in a rat experimental model of asthma
2002
Oxidative stress appears to be relevant to asthma pathogenesis. Therefore, the effectiveness of the antioxidant N -acetylcysteine was examined on antigen-induced pulmonary responses in sensitized Brown-Norway rats. N -acetylcysteine (oral, 1 mmol kg(-1)per day for 7 days before challenge) did not reduce the immediate bronchospasm that followed aerosol antigen exposure but prevented airway hyperreactivity to 5-hydroxytryptamine at 24 h after antigen challenge, and reduced the eosinophils (from 0.178 +/- 0.038 in the absence to 0.064 +/- 0.020 x10(6)cells ml(-1)in the presence of N -acetylcysteine;P< 0.05), and Evans blue dye extravasation in bronchoalveolar lavage fluid. Taurine levels in br…
Sex-dependent changes in the pulmonary vasoconstriction potential of newborn rats following short-term oxygen exposure
2012
Chronic exposure to supplemental oxygen (O(2)) induces lung damage and mortality in a sex-dependent manner. The effect of short-term hyperoxia on the newborn pulmonary vasculature is unknown but is, however, of clinical significance in the neonatal resuscitation context. We hypothesize that short-term hyperoxia has a sex-dependent effect on the pulmonary vasculature.Following 1-h 100% O(2) exposure, the pulmonary arteries and lung tissues of newborn rats were evaluated.Superoxide dismutase 3 (SOD3) expression in female pups' lungs was increased as compared with that in the lungs of male pups. As compared with air-treated pups, the response of male pups to thromboxane was increased by O(2), …
Xanthine oxidase-induced oxidative stress causes activation of NF-κB and inflammation in the liver of type I diabetic rats
2009
We previously showed that xanthine oxidase activity increases in type I diabetic animals and that this is a significant cause of the oxidative stress which occurs in the disease. The aim of this work was to search for molecular links between xanthine oxidase-induced oxidative stress and inflammation in Type I diabetes and to assess the ability of allopurinol, a drug widely used in clinical practice, to prevent both processes. 3-month-old male Wistar rats were made diabetic by injection (i.p.) of either streptozotocin or alloxan. Allopurinol (32 mg/Kg) was administered (i.p) to diabetic rats after they had shown clear signs of diabetes such as glucosuria and polyuria. Hepatic phospho-IKKbeta…
Antioxidant activity of anti-inflammatory plant extracts
2002
The antioxidant properties of twenty medical herbs used in the traditional Mediterranean and Chinese medicine were studied. Extracts from Forsythia suspensa, Helichrysum italicum, Scrophularia auriculata, Inula viscosa, Coptis chinensis, Poria cocos and Scutellaria baicalensis had previously shown anti-inflammatory activity in different experimental models. Using free radical-generating systems H. italicum. I. viscosa and F. suspensa protected against enzymatic and non-enzymatic lipid peroxidation in model membranes and also showed scavenging property on the superoxide radical. All extracts were assayed at a concentration of 100 microg/ml. Most of the extracts were weak scavengers of the hy…
Effect of xanthine oxidase-generated extracellular superoxide on skeletal muscle force generation
2009
Skeletal muscle contractions increase superoxide anion in skeletal muscle extracellular space. We tested the hypotheses that 1) after an isometric contraction protocol, xanthine oxidase (XO) activity is a source of superoxide anion in the extracellular space of skeletal muscle and 2) the increase in XO-derived extracellular superoxide anion during contractions affects skeletal muscle contractile function. Superoxide anion was monitored in the extracellular space of mouse gastrocnemius muscles by following the reduction of cytochrome c in muscle microdialysates. A 15-min protocol of nondamaging isometric contractions increased the reduction of cytochrome c in microdialysates, indicating an …
Topical allopurinol or corticosteroids and acetylcysteine in the early treatment of experimental corneal alkali burns: a pilot study.
2002
PURPOSE. To investigate the effect of topical allopurinol on experimental corneal burns and to compare this to established treatment modalities such as topical prednisolone and acetylcysteine. METHODS. Twenty Wistar rats were randomly assigned to four groups (n=5 each). The groups were controls (normal saline), allopurinol 0.4% eye drops, prednisolone acetate 1% eye drops and acetylcysteine 8% eyedrops. Corneal burn was induced using a 3 mm paper disc soaked in 1N NaOH for 60 seconds. Drops were instilled 6 times per day. In addition, one drop/day ofloxacine was given to prevent secondary infections. Eyes were enucleated 50 hours later and fixed in 4.5% formaldehyde. Three histological leve…
Effect of aging on metabolic zonation in rat liver: acinar distribution of GSH metabolism.
1992
The effect of age on the glutathione antioxidant system and its acinar distribution in rat liver was studied. GSH/GSSG ratio in blood and liver was lower in old than in young rats. Hepatic glutathione peroxidase and glutathione S-transferase activities were higher in old than in young rats, whereas hepatic gamma-glutamyl transpeptidase activity was lower in old than in young rats. Glutathione reductase and glucose-6-phosphate dehydrogenase activities did not change with age in rat liver. Total glutathione levels and glutathione peroxidase activity were higher in periportal than in perivenous areas of young rats, but this heterogeneous distribution did not occur in old rats. No change with a…