RESUMO
The "breath test" based on the measurement of gases in expired air are an alternative to the study of metabolic and functional alterations in gastroenterology. They are classified into two groups based on the molecule analyzed and if the substrate is isotopically labelled or not: H2 and/or CH4 test (malabsorption of sugars, bacterial overgrowth, etc.) and 13CO2 test (infection by H. pylori, exocrine pancreatic function, etc.).
Assuntos
Testes Respiratórios , Doenças do Sistema Digestório/diagnóstico , Gastroenterologia/métodos , Cromatografia Gasosa , Diagnóstico Diferencial , Gases , HumanosAssuntos
Síndrome da Criança Espancada/complicações , Dilatação Gástrica/etiologia , Doença Aguda , Síndrome da Criança Espancada/diagnóstico por imagem , Pré-Escolar , Dilatação Gástrica/diagnóstico por imagem , Humanos , Masculino , Nariz/lesões , Distúrbios Nutricionais/etiologia , Radiografia , Estômago/diagnóstico por imagemRESUMO
The L-arginine analogues NG-monomethyl-L-arginine (L-NMMA, 10(-4) M) and NG-nitro-L-arginine methyl ester (L-NAME, 10(-4) M), which specifically inhibit the synthesis of nitric oxide from L-arginine, significantly reduced acetylcholine-induced endothelium-dependent relaxations in rings of human omental arteries. The inhibitory potency of L-NMMA and L-NAME was similar. Addition of L-NMMA or L-NAME to the organ bath did not induce any significant changes in the resting tension of the tissues. The effects of L-NMMA were reversed by L-arginine (3 x 10(-4) M). The L-NMMA enantiomer, D-NMMA (10(-4) M), did not influence either the basal tone of the preparation or the relaxing effects of acetylcholine. Arterial relaxations induced by sodium nitroprusside (10(-6) M) were not influenced by incubation with L-NMMA or L-NAME. These results suggest that endothelium-dependent relaxations in human omental arteries are mediated by the endogenous and substrate-specific generation of nitric oxide from L-arginine.
