RESUMO
Kerosene is a by product of petroleum used in some countries for cleaning, lighting and cooking purposes. Rodriguez de la Vega et al (1981) have presented evidences of the relation between bronchial asthma and the manipulation of kerosene. Since the experiments performed by our group showed that the acute inhalation of the aerosol of kerosene induces bronchoconstriction in rabbits (Casacó et al 1982), we investigated its effect on guinea pig respiratory physiology. In order to elucidate the implication of histamine and arachidonic acid metabolites in kerosene induced bronchoconstriction, we investigated the influence of the administration to guinea pig of a single dose of the histamine H1 antagonist mepyramine (0.1 mg/kg i.v.) 10 minutes before the aerosol and also the effect of the steroidal antinflammatory drug triamcinolone in rabbits (5 mg/kg i.m.) daily during 4 days before the inhalation of kerosene. The histamine concentrations in guinea pig blood before and after the aerosol were also compared. The inhalation of kerosene during 5 min. (20.4 mg/L) by guinea pigs resulted in an increase of airway resistance without increase of blood histamine concentration. On the other hand, the bronchoconstrictive effect of kerosene in guinea pigs and rabbits was not modified by the previous treatment with mepyramine or triamcinolone respectively. The results suggest that the acute bronchoconstriction induced by kerosene is mediated neither by stimulation of histamine H1 receptors nor by the release of chemical mediators.