title: Beta-adrenoceptor desensitization in a model of experimental asthma in guinea-pigs.
abstract: We investigated the possible occurrence of the desensitization of pulmonary beta-receptors in a model of experimental asthma such as the ovalbumin sensitized guinea-pig. Although some differences were observed between normal and asthmatic guinea-pigs, the desensitization procedure (isoproterenol (ISO) 10(-6) M x 20 min x 2) markedly impaired the relaxing capacity of ISO, epinephrine (EPI) and procaterol. With the beta 2 agonist procaterol, the sensitized tissues seemed to be more sensitive compared to normal. In parallel, the desensitization procedure produced a greater decrease in the relaxing capacity of procaterol in the sensitized tracheas. On the other hand, the two unselective beta-agonists (ISO and EPI) did not seem to discriminate between the two experimental conditions used. These data suggest that the immunological disturbance due to the active sensitization may induce a modification in beta-adrenoceptor reactivity. The results obtained with EPI after anaphylactic challenge are in agreement with this. In fact, the relaxing capacity of EPI was markedly reduced by antigen challenge.
authors.affiliation: Institute of Pharmacological Sciences, University of Milan, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Daffonchio
authors.forename: M P
authors.initials: MP
authors.lastname: Abbracchio
authors.forename: M
authors.initials: M
authors.lastname: Di Luca
authors.forename: R
authors.initials: R
authors.lastname: Pasargiklian
authors.forename: P
authors.initials: P
authors.lastname: Galli
authors.forename: A
authors.initials: A
authors.lastname: Hernandez
authors.forename: C
authors.initials: C
authors.lastname: Omini
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D001249:Asthma / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology; D001985:Bronchial Provocation Tests; D003888:Desensitization, Immunologic; D004195:Disease Models, Animal; D006168:Guinea Pigs; D008297:Male
chemical_list: D000318:Adrenergic beta-Agonists