Skin-derived mast cells retain their capacity to degranulate in response to several agonists after proliferating in vitro.

Anti-FcεRIα mAb (A), substance P (B), and compound 48/80 (C) were assessed as degranulating agents on skin-derived mast cells cultured for 4 to 8 weeks in AIM-V media containing 100 ng/mL rhuSCF. Tryptase release was determined after each agonist was incubated with the mast cells for 15 minutes at 37°C. In each case data are presented as net percent tryptase release. Spontaneous tryptase release values were always less than 5%. Cell viabilities were determined at the high dose of each agonist at the end of the experiment by trypan blue staining, and were observed to be more than 90% in all cases. Bar graphs display mean ± SD values from 3 independent experiments.