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1.
Wound Repair Regen ; 25(2): 320-326, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28370804

RESUMO

Proteases are important for wound healing, but in excessive amounts or left uncontrolled, they may cause healing impairment or other severe wound complications. Point-of-care testing for protease activities in wounds may be useful for monitoring the effectiveness of treatment, and for early identification of wounds that potentially fail to heal. Here we describe an easy, noninvasive method to collect wound fluid for evaluating the protease milieu of wounds. Wound fluids were collected using sterile sponges applied between wound surface and normal wound dressing. Wound fluid could be easily squeezed or centrifuged out of the sponges and was tested for gelatinase (MMP-2 and MMP-9) activities by gel zymography. In addition, we measured polymorphonuclear granulocyte elastase levels by ELISA. Both gelatinases were remarkably stable in sponge derived fluids, as no significant loss was observed even when samples were stored for 3 days at room temperature. Protease levels were highly diverse amongst patients and, in some cases, showed substantial variations in the course of the treatment. The here described wound sponge approach represents a patient-friendly and reliable method to collect wound fluid for evaluating wound healing relevant biomarkers, such as matrix metalloproteinases.


Assuntos
Exsudatos e Transudatos/enzimologia , Peptídeo Hidrolases/metabolismo , Tampões de Gaze Cirúrgicos , Úlcera/enzimologia , Cicatrização/fisiologia , Idoso , Idoso de 80 Anos ou mais , Eletroforese em Gel de Poliacrilamida , Exsudatos e Transudatos/metabolismo , Feminino , Humanos , Masculino , Metaloproteinase 2 da Matriz , Metaloproteinase 9 da Matriz , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
2.
Life Sci ; 93(12-14): 441-7, 2013 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-23900029

RESUMO

AIMS: We examined changes in the expression of a pro-angiogenic factor, vascular endothelial growth factor (VEGF), and an anti-angiogenic factor, endostatin, as well as matrix metalloproteinase (MMP)-2 and MMP-9 in the rat small intestine after administration of indomethacin and investigated the roles of these factors in the healing of indomethacin-induced small intestinal ulcers. MAIN METHODS: Male SD rats were given indomethacin (10mg/kg) p.o. and euthanized at various time points (3-24h and 2-7days) after the administration. To impair the healing of these lesions, low-dose of indomethacin (2mg/kg) was given p.o. once daily for 6days starting 1day after ulceration. Levels of VEGF, endostatin, MMP-2 and MMP-9 were determined by Western blotting. KEY FINDINGS: The expression of both VEGF and endostatin was upregulated after the ulceration. Repeated administration of low-dose indomethacin impaired the ulcer healing with a decrease of VEGF expression and a further increase of endostatin expression, resulting in a marked decrease in the ratio of VEGF/endostatin expression. The levels of MMP-2 and MMP-9 were both significantly increased after the ulceration, but these responses were suppressed by the repeated indomethacin treatment. The healing of these ulcers was significantly delayed by the repeated administration of MMP inhibitors such as ARP-101 and SB-3CT. SIGNIFICANCE: The results confirm the importance of the balance between pro-angiogenic and anti-angiogenic activities in the healing of indomethacin-induced small intestinal damage and further suggest that the increased expression of MMP-2 and MMP-9 is another important factor for ulcer healing in the small intestine.


Assuntos
Anti-Inflamatórios não Esteroides/toxicidade , Indometacina/toxicidade , Enteropatias/enzimologia , Intestino Delgado/enzimologia , Úlcera/enzimologia , Animais , Endostatinas/metabolismo , Enteropatias/induzido quimicamente , Intestino Delgado/irrigação sanguínea , Intestino Delgado/patologia , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Inibidores de Metaloproteinases de Matriz/farmacologia , Neovascularização Fisiológica , Ratos , Ratos Sprague-Dawley , Úlcera/induzido quimicamente , Fator A de Crescimento do Endotélio Vascular/metabolismo , Cicatrização
3.
J Pharmacol Exp Ther ; 341(2): 447-54, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22328575

RESUMO

Small intestinal mucosal injury is a frequent adverse effect caused by nonsteroidal anti-inflammatory drugs (NSAIDs). The underlying mechanisms are not completely understood, but topical (luminal) effects have been implicated. Many carboxylic acid-containing NSAIDs, including diclofenac (DCF), are metabolized to acyl glucuronides (AGs), and/or ether glucuronides after ring hydroxylation, and exported into the biliary tree. In the gut, these conjugates are cleaved by bacterial ß-glucuronidase, releasing the potentially harmful aglycone. We first confirmed that DCF-AG was an excellent substrate for purified Escherichia coli ß-D-glucuronidase. Using a previously characterized novel bacteria-specific ß-glucuronidase inhibitor (Inhibitor-1), we then found that the enzymatic hydrolysis of DCF-AG in vitro was inhibited concentration dependently (IC50 ∼164 nM). We next hypothesized that pharmacologic inhibition of bacterial ß-glucuronidase would reduce exposure of enterocytes to the aglycone and, as a result, alleviate enteropathy. C57BL/6J mice were administered an ulcerogenic dose of DCF (60 mg/kg i.p.) with or without oral pretreatment with Inhibitor-1 (10 µg per mouse, b.i.d.). Whereas DCF alone caused the formation of numerous large ulcers in the distal parts of the small intestine and increased (2-fold) the intestinal permeability to fluorescein isothiocyanate-dextran, Inhibitor-1 cotreatment significantly alleviated mucosal injury and reduced all parameters of enteropathy. Pharmacokinetic profiling of DCF plasma levels in mice revealed that Inhibitor-1 coadministration did not significantly alter the C(max), half-life, or area under the plasma concentration versus time curve of DCF. Thus, highly selective pharmacologic targeting of luminal bacterial ß-D-glucuronidase by a novel class of small-molecule inhibitors protects against DCF-induced enteropathy without altering systemic drug exposure.


Assuntos
Anti-Inflamatórios não Esteroides/toxicidade , Diclofenaco/toxicidade , Glucuronidase/antagonistas & inibidores , Enteropatias/induzido quimicamente , Enteropatias/enzimologia , Animais , Anti-Inflamatórios não Esteroides/farmacocinética , Diclofenaco/farmacocinética , Enterócitos/efeitos dos fármacos , Enterócitos/enzimologia , Enterócitos/metabolismo , Escherichia coli/enzimologia , Escherichia coli/metabolismo , Proteínas de Escherichia coli/antagonistas & inibidores , Proteínas de Escherichia coli/metabolismo , Glucuronidase/metabolismo , Glicoproteínas/farmacologia , Enteropatias/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/enzimologia , Mucosa Intestinal/metabolismo , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/enzimologia , Intestino Delgado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Úlcera/induzido quimicamente , Úlcera/enzimologia , Úlcera/metabolismo
4.
Eur J Pharmacol ; 650(1): 411-7, 2011 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-20969854

RESUMO

Cholinergic anti-inflammatory actions have been shown to result mainly from the activation of α7 nicotinic acetylcholine receptors. Here, we investigated the possible role of α7 nicotinic acetylcholine receptors in the pathogenesis of indomethacin-induced small intestinal ulceration in mice. Male C57BL/6 mice were given indomethacin (10mg/kg, s.c.), and sacrificed 24h later. Nicotine (0.3-3mg/kg) and PNU-282987 (a selective agonist of α7 nicotinic acetylcholine receptors; 1-10mg/kg) were administered i.p. twice, at 0.5h before and 8h after indomethacin treatment, while methyllycaconitine (a selective antagonist of α7 nicotinic acetylcholine receptors; 10mg/kg was administered twice, at 0.5h before each nicotine treatment. Indomethacin caused severe hemorrhagic lesions in the small intestine with marked increases in myeloperoxidase (MPO) activity and inducible nitric oxide synthase (iNOS) expression in the mucosa. Pretreatment with nicotine reduced the severity of intestinal lesions in a dose-dependent manner. The protective effect of nicotine was mimicked by PNU-282987 and significantly attenuated by methyllycaconitine. The increases in MPO activity and iNOS expression induced by indomethacin were also significantly suppressed by nicotine and PNU-282987. Immunohistochemical study showed that the expression of α7 nicotinic acetylcholine receptors was clearly enhanced in the submucosa of the damaged area following indomethacin treatment. These results suggest that the activation of α7 nicotinic acetylcholine receptors ameliorates indomethacin-induced small intestinal ulceration, and that this effect may result from the inhibition of iNOS expression and neutrophil migration.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Indometacina/efeitos adversos , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/metabolismo , Receptores Nicotínicos/metabolismo , Úlcera/induzido quimicamente , Úlcera/metabolismo , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Benzamidas/farmacologia , Compostos Bicíclicos com Pontes/farmacologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Intestino Delgado/enzimologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Óxido Nítrico Sintase Tipo II/genética , Peroxidase/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Tirosina/análogos & derivados , Tirosina/biossíntese , Úlcera/enzimologia , Receptor Nicotínico de Acetilcolina alfa7
5.
Biomaterials ; 29(12): 1785-95, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18241915

RESUMO

Chronic ulcers are an important and costly medical issue, imposing considerable pain, reduced mobility and decreased quality of life. The common pathology in these chronic wounds is excessive proteolytic activity, resulting in degradation of key factors critical to the ulcer's ability to heal. Matrix metalloproteinases (MMPs), a large family of zinc-dependent endopeptidases, have been shown to have increased activity in chronic wound fluid (CWF), with many authors suggesting that they need to be inhibited for the ulcer to heal. The studies we report here show that the excessive MMP activity in CWF can be inhibited with the bisphosphonate alendronate, in the form of a sodium salt, a functionalised analogue, and tethered to a poly(2-hydroxy methacrylate) (PHEMA) hydrogel. Furthermore, these functionalised alendronate hydrogels appear to be biologically inert as assessed in a three-dimensional ex vivo human skin equivalent model. Together, these results highlight the potential use of a tethered MMP inhibitor to inhibit protease activity in wound fluid. This approach may improve wound healing as it still allows MMPs to remain active in the upper cellular layers of the ulcer bed where they perform vital roles in wound healing; thus may offer an attractive new device-orientated wound therapy.


Assuntos
Líquidos Corporais/metabolismo , Difosfonatos/administração & dosagem , Portadores de Fármacos/química , Hidrogéis/química , Inibidores de Metaloproteinases de Matriz , Úlcera/tratamento farmacológico , Úlcera/enzimologia , Cicatrização/efeitos dos fármacos , Difosfonatos/química , Ativação Enzimática/efeitos dos fármacos , Humanos , Teste de Materiais
6.
Br J Dermatol ; 158(5): 951-61, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18284390

RESUMO

BACKGROUND: The pathology of chronic wounds is often characterized by elevated levels of proinflammatory cytokines [e.g. tumour necrosis factor (TNF)-alpha and interleukin (IL)-1beta], proteases [e.g. matrix metalloproteinases (MMPs)] and neutrophil elastase. MMPs specifically have been implicated by a number of studies as the major protease family responsible for the degradation of key factors critical to the ulcer's ability to heal. OBJECTIVES: To assess individual MMPs in chronic wound fluid (CWF) in order to develop improved treatments for chronic ulcers. METHODS: Collagen type I and IV zymography, immunoprecipitation followed by a substrate activity assay, and an indirect enzyme-linked immunosorbent assay were all used to analyse MMP levels in CWF. RESULTS: Our studies demonstrate that there is excessive protease activity in CWF compared with both human serum and acute wound fluid (AWF), which can be specifically attributed to MMPs as determined through a MMP-inhibitor study. Multiple MMPs were immunoprecipitated from the CWF samples and MMP-9 was identified as the predominant protease in CWF, with significantly elevated activity levels in CWF compared with AWF. In addition, the clinical status of the ulcer is directly associated with the amounts of MMP-9 present in the wound fluid. Therefore, this study suggests that higher levels of MMP-9 in chronic wound fluid correlate with a clinically worse wound. CONCLUSIONS: In view of these results, it is hypothesized that a specific inhibitor of MMP-9 could potentially be more therapeutically effective than general MMP inhibitors in modulating chronic ulcers towards a healing state.


Assuntos
Exsudatos e Transudatos/enzimologia , Metaloproteinase 9 da Matriz/metabolismo , Úlcera/enzimologia , Cicatrização/fisiologia , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Colágeno/metabolismo , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
7.
J Med Chem ; 50(10): 2341-51, 2007 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-17447747

RESUMO

1-isoquinolinylguanidines were previously disclosed as potent and selective inhibitors of urokinase-type plasminogen activator (uPA). Further investigation of this template has revealed that incorporation of a 7-sulfonamide group furnishes a new series of potent and highly selective uPA inhibitors. Potency and selectivity can be achieved with sulfonamides derived from a variety of amines and is further enhanced by the incorporation of sulfonamides derived from amino acids. The binding mode of these 1-isoquinolinylguanidines has been investigated by X-ray cocrystallization studies. uPA inhibitor 26 was selected for further evaluation based on its excellent enzyme potency (Ki 10 nM) and selectivity profile (4000-fold versus tPA and 2700-fold versus plasmin). In vitro, compound 26 is able to inhibit exogenous uPA in human chronic wound fluid (IC50=0.89 microM). In vivo, in a porcine acute excisional wound model, following topical delivery, compound 26 is able to penetrate into pig wounds and inhibit exogenous uPA activity with no adverse effect on wound healing parameters. On the basis of this profile, compound 26 (UK-371,804) was selected as a candidate for further preclinical evaluation for the treatment of chronic dermal ulcers.


Assuntos
Antiulcerosos/síntese química , Guanidinas/síntese química , Quinolinas/síntese química , Sulfonamidas/síntese química , Ativador de Plasminogênio Tipo Uroquinase/antagonistas & inibidores , Doença Aguda , Animais , Antiulcerosos/química , Antiulcerosos/farmacologia , Sítios de Ligação , Doença Crônica , Cristalografia por Raios X , Guanidinas/química , Guanidinas/farmacologia , Humanos , Técnicas In Vitro , Modelos Moleculares , Ligação Proteica , Quinolinas/química , Quinolinas/farmacologia , Pele/lesões , Dermatopatias/enzimologia , Relação Estrutura-Atividade , Sulfonamidas/química , Sulfonamidas/farmacologia , Suínos , Úlcera/enzimologia , Ativador de Plasminogênio Tipo Uroquinase/química , Cicatrização/efeitos dos fármacos
8.
J Med Chem ; 46(16): 3514-25, 2003 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-12877590

RESUMO

The pathology of chronic dermal ulcers is characterized by excessive proteolytic activity which degrades extracellular matrix (required for cell migration) and growth factors and their receptors. The overexpression of MMP-3 (stromelysin-1) and MMP-13 (collagenase-3) is associated with nonhealing wounds, whereas active MMPs-1, -2, -9, and -14 are required for normal wound healing to occur. We describe the synthesis and enzyme inhibition profile of (3R)-3-[([(1S)-2,2-dimethyl-1-(([(1S)-2-methoxy-1-phenylethyl]amino)carbonyl)propyl]amino)carbonyl]-6-(3-methyl-4-phenylphenyl)hexanoic acid (UK-370,106, 7), which is a potent inhibitor of MMP-3 (IC(50) = 23 nM) with >1200-fold weaker potency vs MMP-1, -2, -9, and -14. MMP-13, which may also contribute to the pathology of chronic wounds, was inhibited about 100-fold less potently by compound 7. Compound 7 potently inhibited cleavage of [(3)H]-fibronectin by MMP-3 (IC(50) = 320 nM) but not cleavage of [(3)H]-gelatin by either MMP-2 or -9 (up to 100 microM). Compound 7 had little effect, at MMP-3 selective concentrations, on keratinocyte migration over a collagen matrix in vitro, which is a model of the re-epithelialization process. Following iv (rat) or topical administration to dermal wounds (rabbit), compound 7 was cleared rapidly (t(1/2) = 23 min) from plasma, but slowly (t(1/2) approximately 3 days) from dermal tissue. In a model of chronic dermal ulcers, topical administration of compound 7 for 6 days substantially inhibited MMP-3 ex vivo. These data suggest compound 7 is sufficiently potent to inhibit MMP-3-mediated matrix degradation while leaving unaffected cellular migration mediated by MMPs 1, 2, and 9. These properties make compound 7 a suitable candidate for progression to clinical trials in human chronic dermal wounds, such as venous ulcers.


Assuntos
Caproatos/síntese química , Inibidores de Metaloproteinases de Matriz , Inibidores de Proteases/síntese química , Dermatopatias/tratamento farmacológico , Úlcera/tratamento farmacológico , Valina/síntese química , Administração Cutânea , Animais , Caproatos/química , Caproatos/farmacologia , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Doença Crônica , Fibronectinas/química , Gelatina/química , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/fisiologia , Masculino , Metaloproteinase 3 da Matriz/química , Compostos Policíclicos , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Coelhos , Pele/efeitos dos fármacos , Pele/patologia , Dermatopatias/enzimologia , Dermatopatias/patologia , Estereoisomerismo , Relação Estrutura-Atividade , Úlcera/enzimologia , Úlcera/patologia , Valina/análogos & derivados , Valina/química , Valina/farmacologia
9.
Med Sci Monit ; 9(1): CR24-8, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12552246

RESUMO

BACKGROUND: Adenosine deaminase is an enzyme which is postulated to have a role in the generation of gastric mucosal inflammation. The aim of our study was to determine and compare adenosine deaminase activity in the gastric mucosa of patients with chronic gastritis developed in partially resected and intact stomachs. MATERIAL/METHODS: 182 patients were studied, 102 non-operated and 80 after distal gastric resection. Biopsy specimens were taken endoscopically from the gastric mucosa 2 cm proximal to the stoma or corresponding upper third of the intact stomach. Gastritis was classified according to the Sydney system. The activity of adenosine deaminase in the mucosal homogenates was measured by determination of ammonia liberated from the substrate and expressed in nmol NH3/mg protein/min. RESULTS: Adenosine deaminase activity was lower in partially resected than in intact stomachs, regardless of Helicobacter pylori infection. While no difference was found in adenosine deaminase activity between Billroth I and Billroth II procedures in subjects without H. pylori infection, the activity was lower in those with Billroth II procedure in the presence of H. pylori infection. As the severity of gastritis increased, enzyme activity decreased in the mucosa of the intact stomach, but was not significantly altered in the mucosa of the gastric remnant. CONCLUSIONS: Adenosine deaminase activity differs in intact and partially resected stomachs, but it does not appear to be a factor promoting chronic gastritis.


Assuntos
Adenosina Desaminase/metabolismo , Gastrite/enzimologia , Mucosa/enzimologia , Biópsia , Endoscopia , Gastrite/microbiologia , Helicobacter pylori/metabolismo , Humanos , Inflamação , Estômago/enzimologia , Estômago/microbiologia , Neoplasias Gástricas/enzimologia , Neoplasias Gástricas/microbiologia , Úlcera/enzimologia , Úlcera/microbiologia
10.
Biochim Biophys Acta ; 1597(2): 173-92, 2002 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-12044898

RESUMO

L-Glutamine: D-fructose-6-phosphate amidotransferase, known under trivial name of glucosamine-6-phosphate synthase, as the only member of the amidotransferase subfamily of enzymes, does not display any ammonia-dependent activity. This enzyme, catalysing the first committed step in a pathway leading to the eventual formation of uridine 5'-diphospho-N-acetyl-D-glucosamine (UDP-GlcNAc), is an important point of metabolic control in biosynthesis of amino sugar-containing macromolecules. The molecular mechanism of reaction catalysed by GlcN-6-P synthase is complex and involves both amino transfer and sugar isomerisation. Substantial alterations to the enzyme structure and properties have been detected in different neoplastic tissues. GlcN-6-P synthase is inflicted in phenomenon of hexosamine-induced insulin resistance in diabetes. Finally, this enzyme has been proposed as a promising target in antifungal chemotherapy. Most of these issues, especially their molecular aspects, have been extensively studied in recent years. This article provides a comprehensive overview of the present knowledge on this multi-facets enzyme.


Assuntos
Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/fisiologia , Sequência de Aminoácidos , Animais , Antifúngicos/farmacologia , Bactérias/enzimologia , Catálise , Diabetes Mellitus/enzimologia , Inibidores Enzimáticos/farmacologia , Glucose/metabolismo , Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/antagonistas & inibidores , Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/química , Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/genética , Humanos , Inflamação/enzimologia , Resistência à Insulina , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Molecular , Neoplasias/enzimologia , Homologia de Sequência de Aminoácidos , Úlcera/enzimologia
11.
Inflamm Res ; 49(11): 627-32, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11131303

RESUMO

OBJECTIVE: Gastrointestinal damage and bleeding are the major side effects of non-steroidal anti-inflammatory drugs (NSAID), however the mechanisms of this ulcerogenic action are not fully understood. It has recently been proposed that neutrophil-and oxygen radical-dependent microvascular injuries may be important prime events that lead to mucosal injury. In addition, other factors like bile flow, intact bacterial flora or feeding conditions may contribute to the formation of lesions. Ketoprofen is a NSAID that exists as a pair of R(-) and S (+) enantiomers; like other 2-arylpropionic acids, its anti-inflammatory effects resides almost exclusively in the S (+) isomer. The present study was undertaken to explore the role of oxidative stress in the pathogenesis of intestinal injury induced by oral administration of racemic ketoprofen and its enantiomers given as their water soluble tromethamine salts. MATERIAL AND METHODS: Evaluation of intestinal damage and activities of oxidative stress related enzymes such as myeloperoxidase (MPO), xanthine-oxidase (XO) and superoxide dismutase (SOD) were studied in an experimental animal model using refed rats. RESULTS: After the oral treatment followed by a refeeding period of 24 h, ketoprofen (100, 50, 25 mg/Kg b.w.) dose-dependently caused longitudinal ulcers on the mesenteric side of the middle and lower intestine lumen. The intestinal toxicity caused by S(+)-ketoprofen was significantly lower than the effect observed after racemate and R(-) enantiomer treatments (P <0.001), though the bioinversion of R(-)-ketoprofen to S(+)-enantiomer that occurs in the rat has to be considered. XO activity was unaffected by the studied drugs. Enhanced enteropathy by the racemate and its R (-)-enantiomer was correlated with a significant increase of MPO activity as an index of neutrophil infiltration, and a decrease in SOD activity (p<0.05 Vs control). S(+)-ketoprofen did not significantly change these parameters. CONCLUSIONS: These results suggest that reactive oxygen metabolites can contribute significantly to the development of intestinal lesions, and that R(-)-ketoprofen present in racemic preparations can enhance the toxic intestinal effects of S (+)-enantiomer via modification of neutrophil migration and oxidative stress.


Assuntos
Anti-Inflamatórios não Esteroides/toxicidade , Enteropatias/induzido quimicamente , Cetoprofeno/toxicidade , Estresse Oxidativo , Trometamina/toxicidade , Úlcera/induzido quimicamente , Administração Oral , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Enteropatias/enzimologia , Enteropatias/imunologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/enzimologia , Cetoprofeno/administração & dosagem , Masculino , Infiltração de Neutrófilos/efeitos dos fármacos , Peroxidase/metabolismo , Ratos , Ratos Wistar , Estereoisomerismo , Superóxido Dismutase/metabolismo , Trometamina/administração & dosagem , Úlcera/enzimologia , Úlcera/imunologia , Xantina Oxidase/metabolismo
12.
J Physiol Pharmacol ; 50(3): 405-17, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10574470

RESUMO

We investigated the pathogenic role of nitric oxide (NO) in indomethacin-induced intestinal ulceration in rats. Nonfasting animals responded to a single administration of indomethacin (10 mg/kg, s.c.), resulting in multiple hemorrhagic lesions in the small intestine, mostly the jejunum and ileum. The damage was first observed 6 hr after indomethacin, the severity increasing progressively with time up to 24 hr later, accompanied with the gene expression of inducible NO synthase (iNOS) and the increase of nitrite and nitrate (NOx) contents in the mucosa. The ocurrence of damage was significantly prevented when iNOS induction was inhibited by dexamethasone given either once 0.5 hr before or twice 0.5 hr before and 6 hr after indomethacin. Likewise, aminoguanidine (a relatively selective iNOS inhibitor) reduced the severity of damage, irrespective whether given twice or as a single injection 6 hr after indomethacin. By contrast, the non-selective NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) exhibited a biphasic effect, depending on the time of administration; the pre-administration worsened the damage, while the later administration reduced the severity of these lesions, yet both responses occureed in a L-arginine-sensitive manner. Pre-administration of L-NAME, but not aminoguanidine, significantly decreased NOx production in the intestinal mucosa of normal rats, while the increase of NOx production following indomethacin was significantly suppressed by the later administration of aminoguanidine as well as L-NAME. These results suggest that NO exerts a dual action in the pathogenesis of indomethacin-induced intestinal ulceration; NO generated by cNOS is protective against indomethacin, by maintaining the integrity of intestinal mucosa, while NO derived by iNOS plays a key pathogenic role in the ulcerogenic process.


Assuntos
Anti-Inflamatórios não Esteroides/toxicidade , Doenças do Íleo/induzido quimicamente , Indometacina/toxicidade , Doenças do Jejuno/induzido quimicamente , Óxido Nítrico/fisiologia , Úlcera/induzido quimicamente , Animais , Inibidores Enzimáticos/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Guanidinas/farmacologia , Doenças do Íleo/enzimologia , Doenças do Íleo/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/enzimologia , Mucosa Intestinal/metabolismo , Doenças do Jejuno/enzimologia , Doenças do Jejuno/metabolismo , Masculino , NG-Nitroarginina Metil Éster/toxicidade , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/biossíntese , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase/fisiologia , Óxido Nítrico Sintase Tipo I , Óxido Nítrico Sintase Tipo II , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Úlcera/enzimologia , Úlcera/patologia
13.
Br J Pharmacol ; 123(5): 795-804, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9535006

RESUMO

1. In the stomach, prostaglandins protect the gastric mucosa against injuries. One rate-limiting step in prostaglandin synthesis is mediated by prostaglandin endoperoxide synthase (PGHS), the target enzyme of non-steroidal anti-inflammatory drugs (NSAIDs). Two isoforms of PGHS exist: a constitutive (PGHS-1) and an inducible (PGHS-2) enzyme. PGHS-1 is the major source of gastric prostaglandins under physiological conditions. Inhibition of prostaglandin synthesis by traditional NSAIDs such as indomethacin and diclofenac which non-selectively inhibit both PGHS-1 and PGHS-2, causes gastric and intestinal ulceration and delays gastric ulcer healing in chronic models. It has been shown that selective PGHS-2 inhibitors such as L-745,337 (5-methanesulphonamide-6-(2,4-difluorothio-phenyl)-1-inda none) are not ulcerogenic and do not inhibit gastro-intestinal prostaglandin synthesis. However, minimal information is available on the long-term effects of PGHS-2 inhibitors on the healing of previously established gastric injuries. We assessed the cellular localization and expression of PGHS-1 and PGHS-2 during gastric ulcer healing and assessed the effects of L-745,337 on previously established cryoulcers in the rat gastric stomach. 2. PGHS-1 and PGHS-2 were located and quantified by immunohistochemistry during experimental gastric ulcer healing. PGHS-2 immunoreactivity was only negligible in the normal gastric wall, but after gastric ulcerations, it was strongly detected in monocytes, macrophages, fibroblasts and endothelial cells below and between the regenerative glands. PGHS-1 immunoreactivity detected in normal gastric mucosa, disappeared after gastric ulceration in the mucosa adjacent to the ulcer crater. However, it reappeared in the regenerative glands from day 5 onwards. Thus, PGHS-1 and PGHS-2 were located at different sites and their maximal expression followed a different time-sequence. 3. We assessed the effects of L-745,337, indomethacin and diclofenac on gastric ulcer healing and histological healing parameters in rats. L-745,337, indomethacin and diclofenac dose-dependently decreased the healing of gastric ulcers. L-745,337, indomethacin and diclofenac decreased epithelial cell proliferation in the ulcer margin and microvessel density in the ulcer bed on day 8 and increased the thickness of the granulation tissue below the ulcer crater and the gap between both edges of the muscularis mucosae on day 15. Indomethacin and diclofenac, but not L-745,337, decreased synthesis of 6-keto-PGF1alpha and PGE2 in tissue fragments from the stomach and terminal ileum and decreased platelet thromboxane B2 synthesis in clotting whole blood. 4. Dose-response curves for the inhibition of chronic gastric ulcer healing by L-745,337 (administered twice daily intragastrically) showed an ID50 value of 1.7 mg (4.3 micromol) kg(-1). Dose-response curves for the inhibition of PGE2 synthesis in inflammatory exudates in the acute carrageenin sponge rat model, showed ID50 values of 1.1 mg (3.1 micromol) kg(-1) and 1.3 (3.3 micromol) mg kg(-1) for indomethacin and L-745,337, respectively. Thus, inhibition of chronic gastric ulcer healing by L-745,337 occurs within a potentially therapeutic dose-range. 5. In summary, PGHS-2 is markedly accumulated after gastric ulceration in monocytes, macrophages, fibroblasts and endothelial cells in regions of maximal repair activity. Selective inhibition of PGHS-2 by L-745,337 delayed gastric ulcer healing though interference with epithelial cell proliferation, angiogenesis and maturation of granulation tissue in a potentially therapeutic dose range. PGHS-2-derived prostaglandins seem to have an important role in gastric ulcer healing.


Assuntos
Enteropatias/enzimologia , Prostaglandina-Endoperóxido Sintases/efeitos dos fármacos , Úlcera Gástrica/enzimologia , Úlcera/enzimologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/uso terapêutico , Antiulcerosos/farmacologia , Antiulcerosos/uso terapêutico , Inibidores de Ciclo-Oxigenase/farmacologia , Inibidores de Ciclo-Oxigenase/uso terapêutico , Diclofenaco/farmacologia , Diclofenaco/uso terapêutico , Modelos Animais de Doenças , Feminino , Íleo/patologia , Indanos/farmacologia , Indanos/uso terapêutico , Indometacina/farmacologia , Indometacina/uso terapêutico , Enteropatias/tratamento farmacológico , Enteropatias/fisiopatologia , Ratos , Ratos Wistar , Úlcera Gástrica/tratamento farmacológico , Úlcera Gástrica/fisiopatologia , Úlcera/tratamento farmacológico , Úlcera/fisiopatologia
14.
Gut ; 41(3): 344-53, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9378390

RESUMO

BACKGROUND: The "topical" effect of non-steroidal anti-inflammatory drugs (NSAIDs) seems to be an important cause of NSAID induced gastrointestinal damage. AIM: To examine the possible mechanism of the "topical" phase of damage in the small intestine. METHODS: Electron microscopy and subcellular organelle marker enzyme studies were done in rat small intestine after oral administration of indomethacin (doses varied between 5 and 30 mg/kg). The effect of conventional and non-acidic NSAIDs on rat liver mitochondrial respiration was measured in vitro in a Clarke-type oxygen electrode. RESULTS: The subcellular organelle marker enzymes showed mitochondrial and brush border involvement within an hour of indomethacin administration. Electron microscopy showed dose dependent mitochondrial changes following indomethacin administration consistent with uncoupling of oxidative phosphorylation (or inhibition of electron transport) which were indistinguishable from those seen with the uncoupler dinitrophenol. Parenteral indomethacin caused similar changes, but not in rats with ligated bile ducts. A range of NSAIDs, but not paracetamol or non-acidic NSAIDs which have a favourable gastrointestinal tolerability profile, uncoupled oxidative phosphorylation in vitro at micromolar concentrations and inhibited respiration at higher concentrations. In vivo studies with nabumetone and aspirin further suggested that uncoupling or inhibition of electron transport underlies the "topical" phase of NSAID induced damage. CONCLUSION: Collectively, these studies suggest that NSAID induced changes in mitochondrial energy production may be an important component of the "topical" phase of damage induction.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Indometacina/efeitos adversos , Enteropatias/induzido quimicamente , Mitocôndrias Hepáticas/efeitos dos fármacos , Úlcera/induzido quimicamente , Desacopladores/efeitos adversos , Acetaminofen/efeitos adversos , Acetaminofen/química , Administração Oral , Animais , Anti-Inflamatórios não Esteroides/química , Aspirina/efeitos adversos , Aspirina/química , Bile/metabolismo , Biomarcadores/análise , Butanonas/efeitos adversos , Butanonas/química , Indometacina/química , Enteropatias/enzimologia , Enteropatias/patologia , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/ultraestrutura , Masculino , Microscopia Eletrônica , Microvilosidades/efeitos dos fármacos , Microvilosidades/enzimologia , Mitocôndrias Hepáticas/enzimologia , Nabumetona , Fosforilação Oxidativa , Ratos , Ratos Sprague-Dawley , Organismos Livres de Patógenos Específicos , Úlcera/enzimologia , Úlcera/patologia , Desacopladores/química
15.
Ann Ophthalmol ; 14(3): 280-2, 1982 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6979967

RESUMO

A 62-year-old woman had chronic bilateral conjunctival ulceration of the palpebral and bulbar conjunctivae. Conjunctival scrapings for viral, chlamydial, and bacteriologic studies were unrevealing. A conjunctival biopsy specimen was taken and submitted for histopathologic and immunofluorescent studies. Hematoxylin-eosin-stained tissue sections showed lymphocytes, plasma cells, and eosinosphils. Laboratory findings showed serum alpha-1-antitrypsin deficiency. alpha-1-Antitrypsin has a molecular weight of approximately 60,000 and inhibits a number of proteolytic enzymes including cellular trypsin, elastase, collagenase, and proteases. The deficiency of alpha-1-antitrypsin may have caused such enzymes to perpetuate the tissue damage, thus eventuating in chronic ulcerative conjunctivitis. The association of deficient alpha-1-antitrypsin with chronic ulcerative conjunctivitis could thus have been coincidental or a contributing factor to the conjunctival disease.


Assuntos
Doenças da Túnica Conjuntiva/etiologia , Conjuntivite/etiologia , Deficiência de alfa 1-Antitripsina , Doenças da Túnica Conjuntiva/enzimologia , Doenças da Túnica Conjuntiva/imunologia , Conjuntivite/enzimologia , Conjuntivite/imunologia , Feminino , Humanos , Pessoa de Meia-Idade , Úlcera/enzimologia , Úlcera/etiologia , Úlcera/imunologia
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