Inhalation of 0.30 ppm @entity7459 potentiates exercise-induced XXXX in asthmatics.

@entity748 @entity7459 @entity6836 @entity8544 @entity5143
Epidemiologic studies support an association among elevated levels of @entity7459 ( @entity6836 ), increased respiratory symptoms, and alterations in lung function. To determine if low level @entity6836 inhalation potentiates exercise-induced @entity5143 , 15 @entity748 subjects, defined by airway constriction with cold air provocation, inhaled 0.30 ppm (560 micrograms/m3) @entity6836 for 30 min. All asthmatics inhaled either air or 0.30 ppm @entity6836 via a mouthpiece for 20 min at rest followed by 10 min of exercise on a bicycle ergometer at a workload of 300 kpm/min, producing a 3-fold or greater increase in minute ventilation. Our studies @entity8544 (SE)% deposition of inhaled @entity6836 at rest and 87 +/- 1% deposition with exercise (p less than 0.001). @entity7459 inhalation at rest resulted in no significant change in pulmonary function. @entity7459 inhalation plus exercise compared to control (air) exposure plus exercise produced significantly greater reductions in FEV (p less than 0.01) and partial expiratory flow rates at 60% of total lung capacity (p less than 0.05). One hour after completion of @entity6836 exposure and exercise, pulmonary function had returned to baseline values. To determine if @entity6836 exposure caused increased reactivity to a known bronchoconstrictor, @entity748 subjects inhaled cold air (range: -11 +/- 2 degrees C) at 3 successive rates of isocapnic ventilation. The response to cold air was expressed as the respiratory heat exchange required to reduce the FEV by 10% (PD10RHE). Prior @entity6836 exposure potentiated the fall in FEV, PD10RHE, and specific airway conductance (p less than 0.05) after isocapnic cold air hyperventilation, compared to the control exposure.(ABSTRACT TRUNCATED AT 250 WORDS)
