Search results for "endoperoxide"
showing 10 items of 65 documents
Diminished neurogenic femoral artery vasoconstrictor response in a Zucker obese rat model: differential regulation of NOS and COX derivatives.
2014
Objective: Peripheral arterial disease is one of the macrovascular complications of type 2 diabetes mellitus. This study addresses femoral artery regulation in a prediabetic model of obese Zucker rats (OZR) by examining cross-talk between endothelial and neural factors. Methods and Results: Arterial preparations from lean (LZR) and OZR were subjected to electrical field stimulation (EFS) on basal tone. Nitric oxide synthase (NOS) and cyclooxygenase (COX) isoform expression patterns were determined by immunohistochemical labelling and Western blotting. Results indicate significantly reduced noradrenergic contractions in preparations from OZR compared with those of LZR. Functional inhibition …
Estrogens inhibit angiotensin II-induced leukocyte-endothelial cell interactions in vivo via rapid endothelial nitric oxide synthase and cyclooxygena…
2002
Angiotensin II (Ang II) may be a key molecule in the development of atherosclerosis. Because the incidence of coronary atherosclerosis in premenopausal women is lower than that observed in men or postmenopausal women, we have investigated the effect of estrogens on Ang II–induced leukocyte recruitment in vivo using intravital microscopy in the rat mesenteric microcirculation. Superfusion for 60 minutes with Ang II induced a significant increase in leukocyte rolling flux, adhesion, and emigration. Administration of 17-β-estradiol (17-β-E) after 30 minutes of Ang II superfusion produced a reduction of these leukocyte responses by 55.1%, 72.7%, and 70.9%, respectively, an additional 30 minutes…
Response to antiviral therapy and hepatic expression of cyclooxygenases in chronic hepatitis C
2007
OBJECTIVES: The aims of this study were to investigate the expression of cyclooxygenase-1 and cyclooxygenase-2 (COX-1 and COX-2) in chronic hepatitis C (CHC) by immunohistochemistry, based on the hypothesis that COXs expression could vary according to genotype, viral load, liver steatosis, BMI and response to therapy and to determine whether the addition of selective COX inhibitors could have a rationale in increasing the efficacy of antiviral therapy. METHODS: We used 35 formalin-fixed, paraffin-embedded liver tissue samples obtained by needle biopsy from patients with CHC (17F/18M) with one of two types of genotype (1b and 3a). The presence of COX-1 and COX-2 in the cytoplasm of hepatocyt…
Potential role of heme oxygenase-1 in the progression of rat adjuvant arthritis
2004
Rat adjuvant arthritis is an experimental model widely used to evaluate etiopathogenetic mechanisms in chronic inflammation. We have examined the participation of heme oxygenase-1 (HO-1) in this experimental arthritis. In this study, an increased nitric oxide (NO) production in the paw preceded the upregulation of HO-1, whereas selective inhibition of inducible NO synthase (iNOS) after the onset of arthritis decreased HO-1 expression, suggesting that the induction of this enzyme may depend on NO produced by iNOS. Therapeutic administration of the HO-1 inhibitor tin protoporphyrin IX was able to control the symptoms of arthritis. This agent significantly decreased leukocyte infiltration, hyp…
Prostaglandin E2 receptors and COX enxymes in human hepatocellular carcinoma: role in the regulation of cell growth
2008
The aim of this study was to investigate the expression of prostaglandin E 2 receptors (EP 1-4 ), cyclooxygenase-1 (COX-1), and COX-2 in nontumor and tumor human liver tissues, and also to evaluate the antitumor activity of selective EP 1 receptor antagonist used alone or in combination with COX-1 and COX-2 selective inhibitors. Semiquantitative PCR analyses revealed that EP 1-4 , COX-1, and COX-2 mRNA expression was detected in nearly all the tissue samples assayed, although with a high variability between nontumor and tumor tissues. In vitro EP 1 receptor antagonist inhibited anchorage-independent cell growth and reduced the viability of hepatocellular carcinoma (HCC) cells in a dose-depe…
Contribution of endothelin receptors and cyclooxygenase-derivatives to the altered response of the rabbit renal artery to endothelin-1 in diabetes
2006
Abstract The influence of diabetes on regulatory mechanisms and specific receptors implicated in the response of isolated rabbit renal artery to endothelin-1 was examined. Endothelin-1 induced a concentration-dependent contraction that was less potent in arteries from diabetic rabbits than in arteries from control rabbits. Endothelium removal or NG-nitro- l -arginine (L-NOARG) enhanced contractions to endothelin-1 either in control and diabetic arteries. Indomethacin inhibited endothelin-1-induced response in control arteries, but enhanced it in diabetic arteries. In contrast to that observed in rubbed and in L-NOARG treated arteries, in the presence of indomethacin the contractile action o…
The effect of postsurgical administration of a selective cyclo-oxygenase-2 inhibitor on the healing of intrabony defects following treatment with ena…
2003
Regenerative treatment with enamel matrix proteins (EMD) has been shown to promote regeneration in intrabony periodontal defects. However, up to now various postoperative regimens such as the routine administration of nonsteroidal anti-inflammatory drugs (NSAIDs) were often used in combination with enamel matrix proteins. Therefore, it cannot be excluded that the results might have been influenced by the effect of the postoperative medication. The aim of this randomized, controlled, blinded, clinical investigation was to determine the effect of postsurgical administration of a selective cyclo-oxygenase-2 inhibitor on the healing of intrabony periodontal defects following regenerative period…
Protection against 2,4,6-trinitrobenzenesulphonic acid-induced colonic inflammation in mice by the marine products bolinaquinone and petrosaspongioli…
2005
Proinflammatory mediators, namely eicosanoids, reactive oxygen and nitrogen species and cytokines, are clearly involved in the pathogenesis of intestinal bowel disease. bolinaquinone (BQ) and petrosaspongiolide M (PT), two marine products with potent anti-inflammatory action, have been shown to control the production of mediators in acute and chronic inflammatory processes. Hence, we have tested here the hypothesis that BQ and PT could ameliorate inflammation and oxidative stress parameters in 2,4,6-trinitrobenzenesulphonic acid (TNBS)-induced colitis in Balb/c mice. BQ and PT were given orally in doses of 10 or 20mg/kg/day. Treatment of the animals with BQ or PT at the highest dose signifi…
Toll-like receptor 2 mediates prostaglandin E2 production in murine peritoneal macrophages and splenocytes in response to Candida albicans
2004
The involvement of Toll-like receptor 2 (TLR2) and TLR4 in triggering signal transduction pathways leading to prostaglandin E(2) (PGE(2)) production in response to Candida albicans has been studied in cells from wild-type, TLR2-/- and TLR4-/- knockout mice. In vitro PGE(2) production by macrophages challenged with zymosan, yeast or hypha cells was strongly inhibited in TLR2-deficient cells, but not in TLR4-/- cells, as compared to macrophages from wild-type mice. PGE(2) production was dependent on de novo cyclooxygenase-2 (Cox2) synthesis, since unchallenged cells failed to produce PGE(2) and specific Cox2 inhibition during challenge totally blocked PGE(2) production. Similar results were o…
Influence of heme oxygenase 1 modulation on the progression of murine collagen-induced arthritis.
2005
Contains fulltext : 48023.pdf (Publisher’s version ) (Closed access) OBJECTIVE: Heme oxygenase 1 (HO-1) can be induced by inflammatory mediators as an adaptive response. The objective of the present study was to determine the consequences of HO-1 modulation in the murine collagen-induced arthritis (CIA) model. METHODS: DBA/1J mice were treated with an inhibitor of HO-1, tin protoporphyrin IX (SnPP), or with an inducer of HO-1, cobalt protoporphyrin IX (CoPP), from day 22 to day 29 after CIA induction. The clinical evolution of disease was monitored visually. At the end of the experiment, joints were examined for histopathologic changes. Cytokine levels in paws were measured by enzyme-linked…