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RESPIRATORY PHYSIOLOGICAL AND ALLERGIC-TYPE RESPONSES TO AN EXTRACT OF STACHYBOTRYS CHARTARUM IN BALB/C MICE
Citation:
Viana, M. E., N HaykalCoates, S H. Gavett, MJK Selgrade, AND MDW Ward. RESPIRATORY PHYSIOLOGICAL AND ALLERGIC-TYPE RESPONSES TO AN EXTRACT OF STACHYBOTRYS CHARTARUM IN BALB/C MICE. Presented at Society of Toxicology, Nashville, TN, March 17-21, 2002.
Description:
RESPIRATORY PHYSIOLOGICAL AND ALLERGIC-TYPE RESPONSES TO AN EXTRACT OF Stachybotrys chartarum IN BALB/C MICE. ME Viana1, N Haykal-Coates2, S H Gavett2, MJ Selgrade2, and M D W Ward2. 1APR/CVM, NCSU, Raleigh, NC, USA. 2NHEERL, ORD, US EPA, RTP, NC, USA.
Rationale: assess the ability of S. chartarum to cause allergic alterations in respiratory physiological responses similar to those observed in human allergic asthma.
Methods and Results: 5 S. chartarum isolates were grown, combined in approximately equal weight amounts, and extracted to form a crude antigen preparation (SCE-1). BALB/C mice were exposed to 4 aspirations of SCE-1, BSA, or HBSS over a 4-week period. Barometric whole-body plethysmography was performed to measure enhanced pause (PenH) 10 minutes prior to (baseline) and 1 hour following each aspiration exposure to assess immediate respiratory responses. Additionally, airway responses to nebulized methacholine (MCh) was assessed on days 1 and 3 following the 4th aspiration exposure. Serum and bronchioalveolar lavage fluid (BALF) were collected before the 4th aspiration (D0), and at 1, 3, and 7 days after the 4th aspiration, and lungs were fixed for histopathological examination. SCE-1-exposed mice displayed increased BALF total protein and LDH, increased BALF total cell numbers, and differential counts of BALF cells showed neutrophilia, marked eosinophilia, and increased numbers of lymphocytes. Serum and BALF total IgE levels were elevated, and BALF IL-5 levels were greatly increased. Exposure to HBSS or BSA did not alter baseline PenH or PenH following the aspirations, nor did it cause an increase in airway responsiveness to MCh. Exposure to SCE-1 resulted in increased PenH over baseline after the 3rd exposure and 4th exposure, and increased responsiveness to a MCh aerosol challenge. We conclude respiratory SCE-1 exposure causes allergic respiratory physiological responses similar to those observed in human allergic asthma. (Supported by NCSU/EPA Cooperative Training Agreement CT826512010.) (This abstract does not reflect EPA policy.)