Mast cell heterogeneity in response to cholinergic stimulation.

Mast cell heterogeneity in response to acetylcholine has been evidentiated by the virtual lack of sensitivity or by the full reaction to nanomolar concentrations of acetylcholine, observed in samples of serosal mast cells isolated from the same animal species. The incubation with IgE of isolated rat mast cells renders the originally heterogeneous response homogeneous, the release of histamine evoked by acetylcholine being proportional to the IgE concentration. The histamine release induced by acetylcholine is due to the activation of muscarinic receptors, since it is blocked by atropine, not reproduced by acetylthiocholine and potentiated by exposure of the cells to the specific antigen.