title: Influence of cromolyn sodium on airway temperature in normal subjects.
abstract: It is well established that cromolyn sodium attenuates the bronchoconstriction induced by airway cooling in both normal and asthmatic subjects. To determine whether this protection derives from a modification of the thermal events that transpire during the conditioning of inspired air, we first recorded the effect of cromolyn on the bronchoconstrictor response to hyperventilation with frigid air in 7 normal subjects. On a separate occasion, we imposed the same thermal burden and measured the temperature at multiple sites within the airways before and after pretreatment with cromolyn. The first cold air challenge produced a significant decrease in forced expiratory volume in one second (FEV1) of 5.5 +/- 0.9% (SEM) and these changes were significantly reduced by cromolyn (FEV1 = 2.8 +/- 0.9%; p less than 0.05). In concert with the improvement in mechanics, the temperatures (T) within the trachea (tr) and the anterior segment of the right lower lobe (AS-RLL) were significantly higher after cromolyn (Ttr = 1.3 +/- 0.2 degrees C; p less than 0.01; TAS-RLL = 1.0 +/- 0.4 degrees C; p = 0.05), and there was a direct positive relationship between the mechanical protection offered by the drug and the increase in airway temperature (Spearman's rank correlation coefficient = 0.83; p = 0.05). These data suggest that cromolyn modifies respiratory heat exchange in such a fashion as to limit airway cooling. The mechanism of this action is not presently known but may reflect a direct or indirect influence on the bronchial vasculature.
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D001831:Body Temperature / Q000187:drug effects*; D001980:Bronchi / Q000187:drug effects*; D001986:Bronchial Spasm / Q000517:prevention & control; D003080:Cold Temperature; D004205:Cromolyn Sodium / Q000494:pharmacology*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D006985:Hyperventilation / Q000503:physiopathology; D008297:Male; D012016:Reference Values; D014132:Trachea / Q000187:drug effects*
chemical_list: D004205:Cromolyn Sodium