English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Background  Calcitonin gene-related peptide (CGRP) is one of the most potent endogenous vasodilators identified to date. The present study elucidates the differential interaction of CGRP, its receptor and the effect of the CGRP-receptor antagonist telcagepant on intracellular Ca 2+  -levels and tension in rat middle cerebral arteries (MCA) by pressurized arteriography, FURA-2/wire myography and immunohistochemistry.    Methods  A pressurized arteriograph system was used to evaluate changes in MCA tension when subjected to CGRP and/or telcagepant. Intracellular calcium levels were evaluated using a FURA-2/wire myograph system. Localization of the CGRP-receptor components was verified using immunohistochemistry.    Results  Abluminal but not luminal αCGRP (10 -12 -10 -6  M) caused concentration-dependent vasorelaxation in rat MCA. Luminal telcagepant (10 -6  M) failed to inhibit this relaxation, while abluminal telcagepant inhibited the relaxation (10 -6  M). Using the FURA-2 method in combination with wire myography we observed that αCGRP reduced intracellular calcium levels and in parallel the vascular tone. Telcagepant (10 -6  M) inhibited both vasorelaxation and drop in intracellular calcium levels. Both functional components of the CGRP receptor, CLR (calcitonin receptor-like receptor) and RAMP1 (receptor activity modifying peptide 1) were found in the smooth muscle cells but not in the endothelial cells of the cerebral vasculature.    Conclusions  This study thus demonstrates the relaxant effect of αCGRP on rat MCA. The vasorelaxation is associated with a simultaneous decrease in intracellular calcium levels. Telcagepant reduced relaxation and thwarted the reduction in intracellular calcium levels localized in the vascular smooth muscle cells. In addition, telcagepant may act as a non-competitive antagonist at concentrations greater than 10 -8  M.

the journal of headache and pain

Differential inhibitory response to telcagepant on αCGRP induced vasorelaxation and intracellular Ca2+ levels in the perfused and non-perfused isolated rat middle cerebral artery