Heightened cholinergic responsiveness in IgE-producing rabbits

Atopic humans express an array of autonomic nervous system abnormalities. An animal model of IgE-mediated allergy was herein employed to determine if the induction of an IgE antibody response would affect autonomic responsiveness. Rabbits were immunized so as to selectively produce IgE antibodies, and their pupillary miotic and mydriatic responses to cholinergic and alpha adrenergic stimuli, respectively, were determined. IgE-producing rabbits exhibited hyperresponsiveness to cholinergic but not alpha adrenergic stimulation, a pattern resembling that seen in nonasthmatic atopic humans. Repeated sublethal anaphylactic episodes induced in three IgE-producing rabbits did not affect the pattern of autonomic responsiveness when compared to controls challenged with saline, despite clear evidence of increased plasma histamine levels immediately after antigen challenges in the IgE group. This study indicates that elicitation of an IgE antibody response is associated with the concomitant development of cholinergic hyper-responsiveness.