The effects of adenosine and of some adenosine analogues on the concanavalin A-or acetylcholine-induced histamine release from human adenoidal mast cells.

Histamine release induced by concanavalin A (Con A) or acetylcholine is enhanced by adenosine or the adenosine analogues PIA and NECA. The enhancement is not affected by preincubation with adenosine deaminase. The degree of the Con A-induced histamine release decreases with increasing incubation time.

The human adenoidal mast cell. Susceptibility to different secretagogues and secretion inhibitors.

Mast cells from adenoid tissues of man do not form a homogeneous population but differ in size and ultrastructure. They degranulate on stimulation with specific antigen, ionophore A 23187, Concanavalin A and, under certain conditions, antihuman IgE or acetylcholine. Compound 48/80, dextran, purified C3a or C5a are ineffective.