Effects of reactive oxygen species and neutrophils on endothelium-dependent relaxation of rat thoracic aorta
| Autor: | Ružena Sotníková, Katarína Drábiková, Viktor Bauer |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Pathology
medicine.medical_specialty Health Toxicology and Mutagenesis Toxicology chemistry.chemical_compound neutrophils Muscle tension medicine Xanthine oxidase Pharmacology chemistry.chemical_classification Reactive oxygen species biology business.industry Superoxide ROS Molecular biology Respiratory burst aorta chemistry Catalase biology.protein Hydroxyl radical Original Article business Acetylcholine medicine.drug |
| Zdroj: | Interdisciplinary Toxicology |
| ISSN: | 1337-9569 1337-6853 |
| Popis: | Reactive oxygen species (ROS) are produced in different metabolic processes including the respiratory burst of neutrophils accompanying local inflammation. The aim of this study was to analyze the effects of N-formyl-methionyl-leucyl-phenylalanine (FMLP)-activated neutrophils, isolated from the guinea pig peritoneal cavity, on isolated rings of a large (conduit) artery, the rat thoracic aorta. FMLP-activated neutrophils enhanced the basal tension increased by α(1)-adrenergic stimulation. In phenylephrine-precontracted aortae, they elicited marked contraction, while in noradrenaline-precontracted rat aortal rings they caused a biphasic response (contraction-relaxation). To eliminate interaction of activated neutrophils with catecholamines, in the subsequent experiments the basal tension was increased by KCl-induced depolarization. Activated neutrophils evoked a low-amplitude biphasic response (relaxation-contraction) on the KCl-induced contraction. Not only the acetylcholine- and A(23187)-induced relaxations but also the catalase sensitive hydrogen peroxide (H(2)O(2)) elicited contractions were endothelium-dependent. Even though the acetylcholine-induced relaxation was changed by activated neutrophils and by the ROS studied, their effects differed significantly, yet none of them did eliminate fully the endothelium-dependent acetylcholine relaxation. The effect of activated neutrophils resembled the effect of superoxide anion radical (O(2) (•-)) produced by xanthine/xanthine oxidase (X/XO) and differed from the inhibitory effects of Fe(2)SO(4)/H(2)O(2)-produced hydroxyl radical ((•)OH) and H(2)O(2). Thus O(2) (•-) produced either by activated neutrophils or X/XO affected much less the endothelium-dependent acetylcholine-activated relaxation mechanisms than did (•)OH and H(2)O(2). In the large (conduit) artery, the effects of activated neutrophils and various ROS (O(2) (•-), (•)OH and H(2)O(2)) seem to be more dependent on muscle tension than on endothelial mechanisms. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|