Details

Autor(en) / Beteiligte

• Jansen, I.
• Alafaci, C.
• Uddman, R.
• Edvinsson, L.

Titel

Evidence that calcitonin gene-related peptide contributes to the capsaicin-induced relaxation of guinea pig cerebral arteries

Ist Teil von

• Regulatory peptides, 1990-12, Vol.31 (3), p.167-178

Ort / Verlag

Shannon: Elsevier B.V

Erscheinungsjahr

1990

Quelle

Elsevier Journal Backfiles on ScienceDirect (DFG Nationallizenzen)

Beschreibungen/Notizen

• Pretreatment with capsaicin caused a depletion of substance P (SP)-, neurokinin A (NKA)- and calcitonin gene-related peptide (CGRP)-like immunoreactivity (-LI) from the trigeminal ganglion, dura mater and cerebral arteries. The effect of capsaicin on isolated basilar arteries of guinea pig resulted in a biphasic relaxant response of histamine precontracted vessels. The first phase of the capsaicin-induced relaxation was absent in capsaicin-treated guinea pigs. Furthermore, repeated administration of capsaicin decreased the first but not the second phase of relaxation, supporting the view that a stored agent was released, while the second phase probably was due to a direct effect of capsaicin per se. The biphasic effect was not modified by the SP antagonist Spantide in a concentration that blocks tachykinin response (3 · 10 −6 M), nor by removal of the endothelium. There was no significant difference in pD 2 values (− log concentration eliciting half maximum relaxation) between relaxations induced by SP, NKA, neurokinin B, neuropeptide K or CGRP in capsaicin pretreated as compared to vehicle-treated animals. These results are in support of the assumption that CGRP is involved in the capsaicin-induced relaxation caused by release of vasoactive agents from sensory afferent nerves.