Inhalation exposure of trimellitic anhydride (TMA) aerosol in a brown norway rat model.
Lewis-DM; Zhang-X; Siegel-PD
Toxicologist 2004 Mar; 78(S-1):49
Inhalation is one of the TMA exposure routes for sensitization and subsequent asthma. The present work reported some characteristics after inhalation exposure of TMA aerosol. Brown Norway rats (n=8/group) were exposed, once a week from day 0 to day 63 with 40 mg/m 3 TMA or to day 70 with 4 mg/m 3 TMA in a nose-only system for 10 min. Enhanced pause (Penh, an index of airway resistance) was recorded in Buxco chambers overnight 12 hours). Sera were collected weekly for antibody analyses. For the group with 40mg/m 3 of TMA, specific IgE level was significantly increased after day 7 and reached the peak by day 49. By day 14 these rats developed early- (EAR) and late-phase airway responses (LAR) following exposure. For the group exposed to 4mg/m 3 of TMA, specific IgE level was significantly in-creased by day 21 and reached the peak by day 56; however, no obviously airway responses were noted. Two weeks after the final exposure the 4 mg/m 3 TMA exposed rats were challenged with 40 mg/m 3 TMA resulting in both an EAR and LAR response. The specific IgE levels for rats with high dose of TMA were greater than that with low dose of TMA. We conclude that high dose and short term inhalation exposure may induce specific IgE and airway responses; low dose and short term exposure can induce specific IgE production to establish sensitization, while the development of airway responses needs high dose of TMA for challenge.
Inhalation-studies; Exposure-levels; Anhydrides; Aerosols; Laboratory-animals; Animals; Animal-studies; Sensitization; Bronchial-asthma; Airway-obstruction; Airway-resistance
Disease and Injury: Asthma and Chronic Obstructive Pulmonary Disease
The Toxicologist. Society of Toxicology 43nd Annual Meeting and ToxExpo, March 21-25, 2004, Baltimore, Maryland