Sensitivity of human cutaneous mast cells to anaphylactic and nonimmunological stimuli

Mast cells represent significant cellular element of the skin. It is now postulated that they play an important role in cutaneous homeostasis and are engaged in some pathological processes as well. The aim of our study was to examine sensitivity of human cutaneous mast cells to anaphylactic and anaphylactoid stimuli. The studies were performed on human cutaneous mast cells obtained from healthy skin by enzymatic dispersion technique. The mast cells were activated in vitro with anti-IgE, concanavalin A (Con A), compound 48/80, substance P (SP) or tumor necrosis factor alpha (TNF-alpha). We have noticed that skin mast cells were susceptible to the challenge with anti-IgE and Con A, and histamine release was dose- and time-dependent. In both cases histamine release was high (44.0 +/- 4.1% with anti-IgE at dilution 1:500 and 20.1 +/- 2.4% with Con A in concentration 500 micrograms/ml). Cutaneous mast cells were challenged in a dose- and time-related fashion with compound 48/80, however histamine release was low (9.8 +/- 2.4%, at concentration of compound 48/80-100 micrograms/ml). SP and TNF-alpha also activated mast cells but the magnitude of histamine release was not high (up to 7.1 +/- 0.9%, SP in concentration 10(-4) M and 17.4 +/- 1.1%, TNF-alpha in concentration 10(-6) M) and maximal after 20 min reaction.