Brown Norway rats were exposed 30 min to the antigen, ovalbumin (OVA) at 7.2, 68, 93, 111 or 156 mg/m3 on days 1, 8, 15, and 29. Tissue was collected one day after the last exposure. Systeine (CYSH), glutathione (GSH), and markers of inflammation in bronchioalveolar lavage fluid (BALF) were measured. Alveolar macrophage (AM) and pulmonary associated lymph node lymphocyte (PALNL) were isolated and assessed for CYSH and GSH concentrations. Specific IgG and IgE, and lung tissue IFN-gamma, IL-4, and TNF-alpha mRNA levels (standardized with G3PDH) were the immunological endpoints studied. Rats were immunologically sensitized as evident by exposure related increases in all immunological parameters and OVA challenge induced increases in BALF albumin, protien and lcatate dehydrogenase. In addition, OVA caused a modest elevation at low OVA challenges, but sharp reduction in AM thiols at higher OVA challenges. Concomitantly, OVA exposure dependent increases in BALF CYSH and GSH were observed. CYSH, but not GSH was elevated in PALNL of OVA challenged rats. In summary, antigen exposure does dependent alteration of thiol and immune parameters were demonstrated in ova sensitized and challenged rats.
The Toxicologist. Society of Toxicology 41st Annual Meeting and ToxExpo, March 17-21, 2002, Nashville, Tennessee