You are here:
TRIMELLITIC ANHYDRIDE (TMA) HYPERSENSITIVITY IN MICE AFTER DERMAL AND INTRATRACHAEL (IT) EXPOSURES
Citation:
Boykin, E H., MDW Ward, MJK Selgrade, AND D M. Sailstad. TRIMELLITIC ANHYDRIDE (TMA) HYPERSENSITIVITY IN MICE AFTER DERMAL AND INTRATRACHAEL (IT) EXPOSURES. Presented at SOT, San Francisco, CA, March 25-29, 2001.
Description:
ABSTRACT for 2001 DMS213
TRIMELLITIC ANHYDRIDE (TMA) HYPERSENSITIVITY IN
MICE AFTER DERMAL AND INTRATRACHEAL (IT) EXPOSURES. E Boykin, M Ward, MJ Selgrade, and D Sailstad. NHEERL, ORD, US EPA, RTP, NC, USA.
TMA causes respiratory hypersensitivity (RH) responses. While elevated total serum IgE has been reported after dermal exposure to low molecular weight RH chemicals in mice, these results are variable. Previously, our work with TMA indicated that the addition of an IT challenge following dermal sensitization increased some endpoints of RH. However, these results are much lower than RH responses seen in murine models of exposure to proteins. Our goal was to investigate the effect of an additional TMA IT exposure to skin sensitized mice in an effort to produce a more robust murine model for the identification of chemical respiratory sensitizers. Mice were topically sensitized over 3 weeks. Abdomens were exposed to 25% TMA for two consecutive days for two weeks. On the third week TMA was topically applied to the ears. Mice were exposed IT on weeks 5 and 6 with TMA. Serum and bronchoalveolar lavage fluid (BALF) were collected before (0 hr) and 24, 48, 168 hrs after the last IT. BALF total protein and LDH levels increased at 24 and 48 hrs. BALF total cells also increased at 24 hrs and returned to control levels within 48 hrs. Additionally, the neutrophil level remained elevated as compared to the controls through 168 hrs. A low but statistically significant increase in total IgE was seen in the BALF following IT. Serum IgE levels were consistent with levels seen in previous single IT studies. These levels were above control throughout the time course. There was no significant IFN-g response and a suppressed IL-4 response in the BALF. These results indicate sustained sensitization with the additional IT exposure but limited augmentation of endpoints examined. (This abstract does not reflect EPA policy.)