title: Kinetics of the recovery of airway response caused by inhaled histamine.
abstract: The time course of recovery from airway response induced by the inhalation of progressively doubling doses of histamine phosphate (3 to 4 depending on the subject) was studied in 8 asthmatic subjects by serial measurements of lung resistance (RL). For every subject, the time required for functional recovery became longer with increasing histamine doses and/or degrees of airway response. The slopes of the curves obtained from a single exponential fit relating time on the abscissa and functional recovery on the ordinate were significantly (F = 4.9 to 50.0, p less than 0.01) and progressively lower in 7 of 8 instances. This suggested a multiple compartment model, which was confirmed (r2 greater than or equal to 0.95) in 5 subjects by applying a double exponential regression that provided the most satisfactory fit. We conclude that the recovery from airway response caused by inhaled histamine is longer with increasing doses of histamine and/or degrees of airway response. A double-compartment model, a fast one followed by a slow one, fit this pattern of recovery in 5 of the 8 subjects.
mesh_terms: D000328:Adult; D000336:Aerosols; D000403:Airway Resistance / Q000187:drug effects*; D001249:Asthma / Q000503:physiopathology; D005260:Female; D005541:Forced Expiratory Volume; D005740:Gases; D006632:Histamine / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D008168:Lung / Q000503:physiopathology; D008297:Male; D008450:Maximal Midexpiratory Flow Rate; D008875:Middle Aged; D008954:Models, Biological; D012044:Regression Analysis; D013909:Thorax
chemical_list: D000336:Aerosols; D005740:Gases; D006632:Histamine