title: Beta-adrenergic blockade in ponies with recurrent obstructive pulmonary disease.
abstract: Ponies with recurrent airway obstruction have hyperresponsive airways during acute disease exacerbations but not during clinical remission. We examined the effect of beta-adrenergic blockade with propranolol on airway responsiveness to aerosol histamine in six ponies with recurrent airway obstruction and six age- and gender-matched controls. Measurements were made with principal ponies in clinical remission (period A) and during an acute period of airway obstruction (period B). beta-Adrenergic blockade did not change airway responsiveness, dynamic compliance (Cdyn), or pulmonary resistance (RL) in either group of ponies at period A or in the control ponies at period B. In principal ponies at period B, propranolol significantly increased RL but was without effect on Cdyn or airway responsiveness. We conclude that the beta-adrenergic system is involved in the control of central airway caliber in principal ponies at period B but that this system does not seem to be involved in the mechanism of airway hyperresponsiveness to histamine.
authors.affiliation: Pulmonary Laboratory, College of Veterinary Medicine, Michigan State University, East Lansing 48824.
authors.forename: J S
authors.initials: JS
authors.lastname: Scott
authors.forename: R V
authors.initials: RV
authors.lastname: Broadstone
authors.forename: F J
authors.initials: FJ
authors.lastname: Derksen
authors.forename: N E
authors.initials: NE
authors.lastname: Robinson
mesh_terms: D000403:Airway Resistance / Q000187:drug effects; D000818:Animals; D006734:Horse Diseases / Q000503:physiopathology*; D006736:Horses; D008168:Lung / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology*; D008170:Lung Compliance / Q000187:drug effects; D008173:Lung Diseases, Obstructive / Q000503:physiopathology / Q000662:veterinary*; D011433:Propranolol / Q000494:pharmacology*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000502:physiology; D012016:Reference Values
chemical_list: D011943:Receptors, Adrenergic, beta; D011433:Propranolol