title: Disruptive effects of anion secretion inhibitors on airway mucus morphology in isolated perfused pig lung.
abstract: Since anion secretion inhibitors reproduce important aspects of cystic fibrosis (CF) lung disease, the effects of these antagonists on airway mucus morphology were assessed in isolated perfused pig lungs. Maximal inhibitory concentrations of bumetanide and dimethylamiloride, which respectively block Cl- and HCO3- secretion in porcine airways, induced the formation of dense 'plastered' mucus on the airway surface, depletion of periciliary fluid and collapse of cilia. This effect was more pronounced when lungs were also exposed to bethanechol to stimulate submucosal gland secretion, when plastered mucus covered > 98 % of the airway surface. Bethanechol also reduced gland duct mucin content in the absence, but not presence, of the anion secretion inhibitors. Anion secretion inhibitors did not induce measurable increases in goblet cell degranulation. We conclude that inhibition of anion and liquid secretion in porcine lungs disrupts the normal morphology of airway surface mucus, providing further evidence that impaired anion secretion alone could account for critical aspects of CF lung disease.
authors.affiliation: Department of Physiology, College of Medicine, University of South Alabama, Mobile AL 36688, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Trout
authors.forename: Mary I
authors.initials: MI
authors.lastname: Townsley
authors.forename: Amy L
authors.initials: AL
authors.lastname: Bowden
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Ballard
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000465:Algorithms; D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D000838:Anions / Q000378:metabolism*; D018723:Bethanechol / Q000494:pharmacology; D001639:Bicarbonates / Q000378:metabolism; D001980:Bronchi / Q000187:drug effects / Q000378:metabolism; D002034:Bumetanide / Q000494:pharmacology; D002199:Capillary Permeability / Q000502:physiology; D002712:Chlorides / Q000378:metabolism; D003550:Cystic Fibrosis / Q000503:physiopathology; D004232:Diuretics / Q000494:pharmacology; D005088:Exocrine Glands / Q000187:drug effects / Q000378:metabolism; D007545:Isoproterenol / Q000494:pharmacology; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D008854:Microscopy, Electron; D009077:Mucins / Q000378:metabolism; D009079:Mucociliary Clearance / Q000502:physiology; D009093:Mucus / Q000166:cytology / Q000502:physiology*; D010477:Perfusion; D011175:Positive-Pressure Respiration; D011652:Pulmonary Circulation / Q000502:physiology; D013552:Swine; D016707:Tissue Fixation
chemical_list: D000318:Adrenergic beta-Agonists; D000838:Anions; D001639:Bicarbonates; D002712:Chlorides; D004232:Diuretics; D009077:Mucins; D018723:Bethanechol; D002034:Bumetanide; D000584:Amiloride; D007545:Isoproterenol