Pharmacological differentiation of allergic and classically conditioned asthma in the guinea pig.
A whole-body plethysmographic technique was developed and then used to detect experimentally induced asthma in guinea pigs and to assess pharmacological treatments of allergic and classically conditioned attacks. Inhalation of a beta adrenergic compound (isoproterenol) controlled both forms of attack. Atropine and methscopolamine, parasympathetic blocking agents, prevented conditional but not allergic attacks; diphenhydramine, an antihistamine, prevented allergic attacks; and methysergide, which blocks serotonin (which is believed to trigger human asthma), prevented neither. The guinea pig's allergic reaction is probably the result of a bronchospasm induced by histamine released in tissue of the airway by a local combination of allergen and antibody. The conditional attack is believed to be a constriction of the airway mediated by parasympathetic fibers of central origin.
D000818:Animals; D001249:Asthma / Q000188:drug therapy* / Q000209:etiology; D001285:Atropine / Q000627:therapeutic use; D003214:Conditioning, Classical; D003213:Conditioning, Psychological; D004155:Diphenhydramine / Q000627:therapeutic use; D006168:Guinea Pigs; D006967:Hypersensitivity / Q000188:drug therapy*; D007545:Isoproterenol / Q000627:therapeutic use; D008784:Methysergide / Q000627:therapeutic use; D010991:Plethysmography
D001285:Atropine; D004155:Diphenhydramine; D007545:Isoproterenol; D008784:Methysergide