title: Bronchial hyporesponsiveness.
abstract: It is argued that the dose-response curve for asthmatic patients is of a form that would be expected from the in vitro active force length relationship of bronchial smooth muscle if shortening at maximal isometric tension is quasi-isotonic. If this is the case, it may be more important to attempt to explain normal bronchial hyporesponsiveness, in particular whether bronchoconstriction is quasi-isotonic. In vivo response to inhalation depends on change in length of bronchial smooth muscle cells. Further studies should focus on factors influencing change in length rather than change in force.
mesh_terms: D000403:Airway Resistance; D000818:Animals; D001980:Bronchi / Q000294:innervation / Q000503:physiopathology*; D006801:Humans; D066298:In Vitro Techniques; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000503:physiopathology