title: The i.v. infusion of mannitol decreases airway responsiveness to methacholine in asthma.
abstract: Bronchial asthma and chronic obstructive pulmonary disease (COPD) are characterized by airway inflammation and oedema. The oedema of the airway wall may contribute to airway narrowing and hyperresponsiveness by increasing airway wall thickness, by altering airway compliance, or by impairing the transmission of the lung elastic recoil to the airway smooth muscle (ASM). We hypothesized that the i.v. infusion of mannitol, an osmotic diuretic, would reduce the water content of the airway wall in asthma and COPD, thus decreasing airway responsiveness to methacholine (MCh). In eight asthmatic and in six COPD patients, airway responsiveness to MCh, lung volumes and lung mechanics were measured before and after infusion of mannitol. In the asthmatics, mannitol decreased airway responsiveness to MCh and lung elastic recoil. In the COPD patients, no differences were recorded after mannitol infusion. These data suggest that the airway wall oedema, in asthma, has an impact on airway responsiveness to MCh. The differential effect of mannitol in asthma versus COPD, may relate to the specific pathologic features of the diseases.
authors.affiliation: Divisione di Pneumologia, Ospedale Ninetto Melli, San Pietro Vernotico, Via Lecce 246-72027, San Pietro Vernotico, Brindisi, Italy. div.pneumo@tiscali.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Valerio
authors.forename: Francesco G
authors.initials: FG
authors.lastname: Salerno
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Bracciale
mesh_terms: D000403:Airway Resistance / Q000502:physiology; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D016085:Bronchoconstrictor Agents / Q000037:antagonists & inhibitors* / Q000627:therapeutic use*; D004232:Diuretics / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008353:Mannitol / Q000008:administration & dosage / Q000009:adverse effects*; D016210:Methacholine Chloride / Q000037:antagonists & inhibitors* / Q000627:therapeutic use*; D008875:Middle Aged; D009997:Osmotic Pressure; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology; D012129:Respiratory Function Tests; D015656:Respiratory Mechanics / Q000502:physiology
chemical_list: D016085:Bronchoconstrictor Agents; D004232:Diuretics; D016210:Methacholine Chloride; D008353:Mannitol