title: Effects of beta 2-adrenoceptor agonists on anti-IgE-induced contraction and smooth muscle reactivity in human airways.
abstract: 1. The beta 2-adrenoceptor agonists, salbutamol, salmeterol and RP 58802 relaxed basal tone of human isolated bronchial smooth muscle. Salmeterol- and RP 58802-induced relaxations persisted for more than 4 h when the medium was constantly renewed after treatment. 2. Salbutamol, salmeterol and RP 58802 reversed histamine-induced contractions in human airways (pD2 values: 6.15 +/- 0.21, 6.00 +/- 0.19 and 6.56 +/- 0.12, respectively). 3. Anti-IgE-induced contractions were significantly inhibited immediately after pretreatment of preparations with beta 2-adrenoceptor agonists (10 microM). However, when tissues were treated with beta 2-agonists and then washed for a period of 4 h, salmeterol was the only agonist which significantly inhibited the anti-IgE response. 4. Histamine response curves were shifted to the right immediately after pretreatment of tissues with the beta 2-adrenoceptor agonists (10 microM; 20 min), but maximal contractions were not affected. After a 4 h washing period, the histamine curves were not significantly different from controls. Concentration-effect curves to acetylcholine (ACh) or leukotriene C4 (LTC4) were not significantly modified after beta 2-agonist pretreatment. 5. These results suggest that beta 2-adrenoceptor agonists may prevent anti-IgE-induced contraction by inhibition of mediator release rather than alterations of those mechanisms involved in airway smooth muscle contraction.
authors.affiliation: CNRS URA 1159, Centre Chirurgical Marie Lannelongue, Le Plessis Robinson, France.
authors.forename: I
authors.initials: I
authors.lastname: Gorenne
authors.forename: C
authors.initials: C
authors.lastname: Labat
authors.forename: X
authors.initials: X
authors.lastname: Norel
authors.forename: V
authors.initials: V
authors.lastname: De Montpreville
authors.forename: M C
authors.initials: MC
authors.lastname: Guillet
authors.forename: I
authors.initials: I
authors.lastname: Cavero
authors.forename: C
authors.initials: C
authors.lastname: Brink
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D058666:Adrenergic beta-2 Receptor Agonists; D001980:Bronchi / Q000187:drug effects*; D006632:Histamine / Q000494:pharmacology; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D066298:In Vitro Techniques; D017997:Leukotriene C4 / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009129:Muscle Tonus / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D017997:Leukotriene C4; D007073:Immunoglobulin E; D006632:Histamine; D000109:Acetylcholine