Basenji-Greyhound dog model of asthma: influence of atropine on antigen-induced bronchoconstriction.
To test the relative importance of cholinergic effects on the Basenji-Greyhound (BG) model of asthma, we administered Ascaris antigen to Ascaris-sensitive BG dogs without other treatment, and following intravenous atropine. Pulmonary resistance (RL) increased from 1.4 +/- 0.43 cmH2O . l-1 . s (mean + SE) to 26.0 +/- 5.21 after Ascaris antigen exposure in seven untreated dogs. In the same dogs pretreated with 0.2 mg/kg atropine, RL increased from 1.5 +/- 0.31 to 18 +/- 5.00. Atropine 0.4 and 1.0 mg/kg did not result in increased protection. Although 0.2 mg/kg atropine markedly inhibited the airway responses to both inhaled citric acid and methacholine, it only slightly prevented antigen-induced airway constriction. We conclude that in BG dogs, cholinergic pathways elicit bronchomotor responses to irritants but that the major component of antigen-induced bronchoconstriction is not cholinergically mediated.
D000818:Animals; D000941:Antigens / Q000009:adverse effects*; D001200:Ascaris / Q000276:immunology; D001249:Asthma / Q000503:physiopathology*; D001285:Atropine / Q000494:pharmacology*; D001980:Bronchi / Q000187:drug effects* / Q000503:physiopathology; D002951:Citrates / Q000494:pharmacology; D004195:Disease Models, Animal; D004285:Dogs; D008170:Lung Compliance / Q000187:drug effects; D008688:Methacholine Compounds / Q000494:pharmacology; D012018:Reflex; D014630:Vagus Nerve / Q000502:physiology
D000941:Antigens; D002951:Citrates; D008688:Methacholine Compounds; D001285:Atropine