[The reactivity of dispersed human lung mast cells and peripheral blood basophils to acetylcholine].

To clarify the relation between human lung mast cells and parasympathetic nerve function as well as IgE mediated allergic reactions, highly purified dispersed human lung mast cells were obtained by using the techniques of scissors dispersion, enzymatic treatment, percoll centrifugation and exclusion of adherent cells. The reactivity to acetylcholine was examined by observing the histamine release of purified mast cells. Moreover, peripheral blood basophils, which have many functional similarities with mast cells, were also examined in the same manner. The following results were obtained; 1) Histamine was significantly released from dispersed human lung mast cells at a final concentration of 10(-5) M acetylcholine (p less than 0.05); the peak of histamine release was 10(-4) M of acetylcholine. Acetylcholine had the additional effect of releasing histamine in response to anti-IgE. Histamine release was partially inhibited by 10(-5) M atropine. 2) Basophils had no response to acetylcholine. These results suggest that human lung mast cells play an important role in the defensive mechanism as an effector cell of acetylcholine-mediated autonomic nerve system as well as IgE-mediated allergic reaction.