Dural mast cell degranulation is a putative mechanism for headache induced by PACAP-38

TY - JOUR

T1 - Dural mast cell degranulation is a putative mechanism for headache induced by PACAP-38

AU - Baun, Michael

AU - Pedersen, Martin Holst Friborg

AU - Olesen, Jes

AU - Jansen-Olesen, Inger

PY - 2012/3

Y1 - 2012/3

N2 - Background: Pituitary adenylate cyclase activating peptide-38 (PACAP-38) has been shown to induce migraine in migraineurs, whereas the related peptide vasoactive intestinal peptide (VIP) does not. In the present study we examine the hypothesis that PACAP-38 and its truncated version PACAP-27 but not VIP cause degranulation of mast cells in peritoneum and in dura mater. Methods: The degranulatory effects of PACAP-38, PACAP-27 and VIP were investigated by measuring the amount of N-acetyl-β-hexosaminidase released from isolated peritoneal mast cells and from dura mater attached to the skull of the rat in vitro. In peritoneal mast cells N-truncated fragments of PACAP-38 (PACAP(6-38), PACAP(16-38) and PACAP(28-38)) were also studied. To investigate transduction pathways involved in mast cell degranulation induced by PACAP-38, PACAP-27 and VIP, the phospholipase C inhibitor U-73122 and the adenylate cyclase inhibitor SQ 22536 were used. Results: The peptides induced degranulation of isolated peritoneal mast cells of the rat with the following order of potency: PACAP-38 = PACAP(6-38) = PACAP(16-38) PACAP-27 = VIP = PACAP(28-38). In the dura mater we found that 10 -5 M PACAP-38 was significantly more potent in inducing mast cell degranulation than the same concentration of PACAP-27 or VIP. Inhibition of intracellular mechanisms demonstrated that PACAP-38-induced degranulation is mediated by the phospholipase C pathway. Selective blockade of the PAC 1 receptor did not attenuate degranulation. Conclusion: These findings correlate with clinical studies and support the hypothesis that mast cell degranulation is involved in PACAP-induced migraine. PACAP-38 has a much stronger degranulatory effect on rat peritoneal and dural mast cells than VIP and PACAP-27. The difference in potency between PACAP-38- and PACAP-27/VIP-induced peritoneal mast cell degranulation is probably not related to the PAC 1 receptor but is caused by a difference in efficacy on phospholipase C.

AB - Background: Pituitary adenylate cyclase activating peptide-38 (PACAP-38) has been shown to induce migraine in migraineurs, whereas the related peptide vasoactive intestinal peptide (VIP) does not. In the present study we examine the hypothesis that PACAP-38 and its truncated version PACAP-27 but not VIP cause degranulation of mast cells in peritoneum and in dura mater. Methods: The degranulatory effects of PACAP-38, PACAP-27 and VIP were investigated by measuring the amount of N-acetyl-β-hexosaminidase released from isolated peritoneal mast cells and from dura mater attached to the skull of the rat in vitro. In peritoneal mast cells N-truncated fragments of PACAP-38 (PACAP(6-38), PACAP(16-38) and PACAP(28-38)) were also studied. To investigate transduction pathways involved in mast cell degranulation induced by PACAP-38, PACAP-27 and VIP, the phospholipase C inhibitor U-73122 and the adenylate cyclase inhibitor SQ 22536 were used. Results: The peptides induced degranulation of isolated peritoneal mast cells of the rat with the following order of potency: PACAP-38 = PACAP(6-38) = PACAP(16-38) PACAP-27 = VIP = PACAP(28-38). In the dura mater we found that 10 -5 M PACAP-38 was significantly more potent in inducing mast cell degranulation than the same concentration of PACAP-27 or VIP. Inhibition of intracellular mechanisms demonstrated that PACAP-38-induced degranulation is mediated by the phospholipase C pathway. Selective blockade of the PAC 1 receptor did not attenuate degranulation. Conclusion: These findings correlate with clinical studies and support the hypothesis that mast cell degranulation is involved in PACAP-induced migraine. PACAP-38 has a much stronger degranulatory effect on rat peritoneal and dural mast cells than VIP and PACAP-27. The difference in potency between PACAP-38- and PACAP-27/VIP-induced peritoneal mast cell degranulation is probably not related to the PAC 1 receptor but is caused by a difference in efficacy on phospholipase C.

U2 - 10.1177/0333102412439354

DO - 10.1177/0333102412439354

M3 - Journal article

C2 - 22421901

SN - 0333-1024

VL - 32

SP - 337

EP - 345

JO - Cephalalgia

JF - Cephalalgia

IS - 4

ER -