Site of Respiratory Reaction in Allergic Rats Challenged via the Airways

Abstract

Rats systemically sensitized to DNP-ovalbumin show a characteristic respiratory response to antigen challenge delivered via the airway. The slowing of expiratory air flow which occurs on aerosol challenge still occurs when the antigen is injected via a tracheostomy but not when it is delivered solely to the upper airways. Disodium cromoglycate administered via the tracheostomy 1 min before intratracheal antigen challenge reduces the respiratory response.

Antigen-induced bronchial anaphylaxis in actively sensitized SD rats: Effects of immunization and provocation doses of allergen and of pretreatment with DSCG, theophylline, terbutaline, and methysergid

“…They were kept under sumably due to the action of IgE antibodies conventional conditions. injection of ovalbumin Astra, Sodertalje), 10 mg amorphous Silica (OA) in alum or B. pertussis (8,9). Church and coworkers sen-min (OA; Sigma grade III, crystallized and lyositized animals by injection of the nematode philized) in 0.5 ml saline containing 100 mg Nippostrongylus brasiliensis (11,12,14).…”

“…Church dried and resuspended A1(OH)3 (E 2200 Reheis & Miller (15), like Stotland & Share (32,33) and Chemical Company, obtained through AB others (17,26), used i.p. injection of ovalbumin Astra, Sodertalje), 10 mg amorphous Silica (OA) in alum or B. pertussis (8,9). Casey & (Aerosil, particle diameter 25-50 nm, Degussa, Abboa-Offei challenged normal rats with anti-Erankfurt am Main, obtained via Mataki, IgE (10), whereas passively sensitized animals Malmo, Sweden) or no addition of adjuvant, were examined by Church (11) and by Earmer Selected groups of animals were given booster et al (18).…”

Respiratory Functional Changes on Intratracheal Challenge of Sensitized Rats

“…A difference in structure of the respiratory system in our inbred rat strain perhaps similar to that producing structu ral change in waltzing mice [9] could also explain our results. The expiratory-flow notching has been demonstrable as a fea ture of pulmonary hypersensitivity in the rat over a period of years and throughout the total year [2][3][4] and plethysmographic recordings by other workers on different rat strains [12] confirms its reality and im ply that it is a characteristic biologic re sponse of the rat. The significant correla tion demonstrated between expiratory flow notching and airways resistance in crease suggests some linkage between an airways effect and the expiratory notch ing.…”

“…Acute antigen challenge resulted in an increase in resid ual volume while chronic antigen expo sure, which led toa fall in functional resid ual capacity produced by chronic aerosol exposure in their guinea pigs, resembled allergic alveolitis rather than asthma. Our previous work [2][3][4] does suggest that the process whereby the antigen delivered via the airways reacts with IgE and mast cells is similar to that occurring in human asthma. The sensitized rat is still an ap propriate animal for detailed studies of the mechanisms whereby antigen reaches mast cells in vivo.…”

“…It is difficult to ob tain pulmonary tissue or to conduct prop erly controlled experiments in humans and accordingly attempts have been made to examine the immediate hypersensitivity response of sensitized animals such as dogs and monkeys or guinea pigs [7,20] to antigenic challenge. We have developed a rat model of immediate pulmonary hyper sensitivity which is IgE dependent [2,3]. …”