Enhanced bronchoalveolar lavage mast cells histamine releasability in allergic dogs with and without airway hyperresponsiveness

To determine if mast cells from the airway lumen of Basenji-greyhound (BG) dogs differ functionally from mast cells of control dogs, we compared spontaneous release and A 23187-induced and C5-induced histamine release from bronchoalveolar lavage (BAL) fluid of 14 BG and five allergic and five nonallergic control dogs. No dog received antigen, agonist, or therapeutic aerosols for 4 weeks before BAL. The fluid recovered was centrifuged, and the number of mast cells was quantitated. Aliquots containing equal numbers of mast cells were incubated with A 23187 or C5 for 30 minutes, and histamine release was measured by an automated fluorometric method. Spontaneous release, A 23187-induced release, C5-induced release, and total histamine content per mast cell were calculated. The total amount of histamine per mast cell was not significantly different in BGs and allergic and nonallergic control dogs. Mast cells obtained by BAL released histamine to A 23187 and C5 in a dose-related manner. Spontaneous histamine release and A 23187-induced histamine release was significantly greater in BGs and allergic control dogs compared to nonallergic control dogs. C5-induced histamine release was significantly greater in BGs than in allergic as well as nonallergic control dogs. These data suggest that BAL mast cell histamine releasability must be defined with respect to each stimulus and that mast cells obtained from BAL from control dogs differ with respect to histamine releasability from mast cells of allergic dogs with and without airway hyperresponsiveness. This study suggests that mast cells obtained from BAL can be used to study mast cell function in the control and the allergic state.