Evaluation of inhaled carbon monoxide as an anti-inflammatory therapy in a nonhuman primate model of lung inflammation.
Am J Physiol Lung Cell Mol Physiol
; 299(6): L891-7, 2010 Dec.
Article
em En
| MEDLINE
| ID: mdl-20729385
ABSTRACT
Carbon monoxide (CO) confers anti-inflammatory protection in rodent models of lung injury when applied at low concentration. Translation of these findings to clinical therapies for pulmonary inflammation requires validation in higher mammals. We have evaluated the efficacy of inhaled CO in reducing LPS-induced lung inflammation in cynomolgus macaques. LPS inhalation resulted in profound neutrophil influx and moderate increases in airway lymphocytes, which returned to baseline levels within 2 wk following exposure. CO exposure (500 ppm, 6 h) following LPS inhalation decreased TNF-α release in bronchoalveolar lavage fluid but did not affect IL-6 or IL-8 release. Lower concentrations of CO (250 ppm, 6 h) did not reduce pulmonary neutrophilia. Pretreatment with budesonide, a currently used inhaled corticosteroid, decreased LPS-induced expression of TNF-α, IL-6, and IL-8, and reduced LPS-induced neutrophilia by â¼84%. In comparison, CO inhalation (500 ppm, for 6 h after LPS exposure) reduced neutrophilia by â¼67%. Thus, inhaled CO was nearly as efficacious as pretreatment with an inhaled corticosteroid at reducing airway neutrophil influx in cynomolgus macaques. However, the therapeutic efficacy of CO required relatively high doses (500 ppm) that resulted in high carboxyhemoglobin (COHb) levels (>30%). Lower CO concentrations (250 ppm), associated with anti-inflammatory protection in rodents, were ineffective in cynomolgus macaques and also yielded relatively high COHb levels. These studies highlight the complexity of interspecies variation of dose-response relationships of CO to COHb levels and to the anti-inflammatory functions of CO. The findings of this study warrant further investigations for assessing the therapeutic application of CO in nonhuman primate models of tissue injury and in human diseases. The study also suggests that akin to many new therapies in human diseases, the translation of CO therapy to human disease will require additional extensive and rigorous proof-of-concept studies in humans in the future.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pneumonia
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Administração por Inalação
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Monóxido de Carbono
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Modelos Animais de Doenças
Tipo de estudo:
Prognostic_studies
Limite:
Animals
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Humans
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Male
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article