RELEASE OF HISTAMINE FROM DURAL MAST-CELLS BY SUBSTANCE-P AND CALCITONIN-GENE-RELATED PEPTIDE

The aim of the present study was to examine if the neuropeptides subst ance P (SP), calcitonin gene-related peptide (CGRP), neuropeptide Y (N PY) and vasoactive intestinal peptide (VIP) can stimulate histamine re lease from mast cells in the dura mater and thereby play a role in cra nial vasoregulation and local neurogenic inflammation. Dura mater mast cells were compared with peritoneal mast cells in the rat. Histamine was released from dura mater mast cells by compound 48/80, SP and CGRP but from peritoneal mast cells only by compound 48/80 and SP. NPY and VIP released quite small amounts of histamine from dural mast cells. The release of SP and CGRP from rat dura mater mast cells was blocked by the receptor-antagonists FK888 and CGRP(8-37) respectively, suggest ing receptor mediated release mechanisms. None of the stimuli released histamine from human or porcine dural mast cells, possibly because th e sampling procedure injures and incapacitates the cells.