In the present study the effect of intradermal PACAP-injection on dermal oe
dema in mice was investigated and the contribution of mast cells to this re
sponse was assessed. The injection of PACAP 1-38 into the ears of C57BL/6 m
ice evoked a dose-dependent response, which, after higher doses of PACAP 1-
38, lasted at least 24 h. Histological examination showed significant mast
cell degranulation induced by PACAP. Using mast cell-deficient WBB6F(1)-Kit
(W)/Kit(W-nu) mice and the congenic mice, we demonstrated that the the earl
y phase (30 min to 6 h) of PACAP-induced ear swelling response was signific
antly diminished in mast cell-deficient mice, suggesting that mast cell deg
ranulation contributes to this phase of the response. When mast cell-defici
ent WBB6F(1)-Kit(W)/Kit(W-nu) mice were locally and selectively reconstitut
ed by adoptive mast cell transfer, the dermal oedema was almost equal to th
at of control animals in the early phase of PACAP injection. These results
show that mast cell degranulation contributes to PACAP-induced dermal oedem
a in mice. (C) 1999 Elsevier Science B.V. All rights reserved.