Male Fisher 344 rats were exposed to 2 mg vanadium (V)/m3 (as ammonium metavanadate NH4VO3,0.32 mum MMD) atmospheres for 8 hr/day for 4 days in a nose-only exposure system.
In exposed rats, lung V burdens increased in a time-dependent fashion.
Analysis of lung cells and lavage fluid 24 hr after the final exposure suggested that tissue damage and a strong inflammatory response was elicited ; numbers of neutrophil and small macrophages (Mphi), as well as levels of lavageable protein and lactate dehydrogenase, were significantly elevated as compared with levels observed with air-exposed rats.
Vanadium also affected pulmonary alveolar Mphi (PAM) capacities to produce and respond to immunoregulating cytokines.
Inducible PAM production of tumor necrosis factor-alpha was significantly inhibited, as was the ability to increase cell surface Class II/I-A molecule expression in response to interferon-gamma (IFNgamma).
PAM from V-exposed hosts were also inhibited in their ability to be primed by IFNgamma to produce superoxide anion and hydrogen peroxide in response to stimulation with opsonized zymosan.
These studies indicate that short-term repeated exposure of rats to atmospheric V, at levels encountered in an occupational setting, can alter host pulmonary immunomocompetence, with one major effect occurring at the level of cytokine-related functions. (...)
Mots-clés Pascal : Toxicité, Ammonium Métavanadate, Composé minéral, Inhalation, Rat, Rodentia, Mammalia, Vertebrata, Animal, Système immunitaire, Cytokine, Interféron gamma, Facteur nécrose tumorale alpha, Immunopathologie, Poumon, Inflammation, Appareil respiratoire pathologie, Court terme, Dose répétée, Exposition professionnelle, Médecine travail
Mots-clés Pascal anglais : Toxicity, Ammonium Metavanadates, Inorganic compound, Inhalation, Rat, Rodentia, Mammalia, Vertebrata, Animal, Immune system, Cytokine, Gamma interferon, Tumor necrosis factor alpha, Immunopathology, Lung, Inflammation, Respiratory disease, Short term, Multiple dose, Occupational exposure, Occupational medicine
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 96-0493853
Code Inist : 002B03L03. Création : 10/04/1997.