Persistent specific airway responsiveness in rats sensitized to and challenged with trimellitic anhyrdride (TMA).
Siegel-PD; Zhang-X; Lewis-DM
Toxicologist 2004 Mar; 78(S-1):48
TMA is an organic acid anhydride that is widely used in industry. It can induce specific IgE and cause occupational asthma in sensitized individuals. Persistent occupational asthma, even with antigen/hapten avoidance can be seen is approximately 20% of the cases. Duration of both circulating TMA-specific IgE and specific airway responsiveness was studied in a TMA sensitized Brown Norway rat asthma model as possible contributory factors to persistent asthma. TMA powder (4 mg) was applied to 4 anesthetized rats' backs (clipped with scissors) on days 0, 7, 14 and 21 and washed off after 4 hrs. Specific IgE analyses and airway challenge with TMA (40 mg/m 3 for 10 min) were performed on day 35 and day 386. The ELISA OD values for TMA-specific IgE were 0.46 +/- 0.07 and 0.12 +/- 0.02 on day 35 and day 386, respectively (non-specific binding from control sera OD=0.08 +/- 0.002). Dual, early- (EAR) and late-phase (LAR) airway responses (indicated by enhanced pause, an index of airway resistance) were observed on day 35. A dual response was noted upon rechallenge on day 386 in 3 rats and LAR-only in the 4th rat. These results demonstrate the persistence of specific airway responsive-ness to TMA, even though circulating specific-IgE had drastically declined.
Airway-obstruction; Airway-resistance; Laboratory-animals; Animals; Animal-studies; Organic-acids; Bronchial-asthma; Models; Pulmonary-system-disorders; Respiratory-system-disorders
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