HCGRP-(8-37)

HCGRP-(8-37) (Human α-CGRP (8-37)) is a fragment of human calcitonin gene-related peptide (hCGRP) and an antagonist of the CGRP receptor, with an IC₅₀ of 32.1 pM against the CGRP receptor. HCGRP-(8-37) blocks adenylate cyclase activation induced by CGRP receptor ligands and attenuates vascular responses triggered by CGRP. HCGRP-(8-37) reduces capsaicin-induced vasodilation in porcine nasal mucosa and superficial skin. HCGRP-(8-37) serves as a research tool to distinguish effects mediated by CGRP or calcitonin receptors, and to investigate CGRP-induced vascular effects^[1][2]. IC50 & Target:CGRP receptor^[1] In Vitro:HCGRP-(8-37) (10 min at 37°C) acts as a CGRP receptor antagonist in rat liver plasma membranes. It inhibits CGRP- and calcitonin-induced adenylate cyclase activation in a dose-dependent manner, but does not affect basal, epinephrine- or glucagon-stimulated activities^[1].
HCGRP-(8-37) (60 min at 37°C) binds to calcitonin receptors in LLC-PK₁ porcine kidney cells in a dose-dependent manner^[1].
HCGRP-(8-37) (15 min at 37°C) acts as a calcitonin receptor agonist in LLC-PK₁ porcine kidney cells, which dose-dependently stimulates cAMP production without antagonizing calcitonin- or CGRP-induced cAMP production^[1].
HCGRP-(8-37) potently inhibits CGRP-mediated adenylate cyclase activation in cell-free rat liver plasma membrane preparations^[2]. In Vivo:HCGRP-(8-37) (16 µM; local intra-arterial infusion; 20 minutes) significantly attenuates both CGRP- and capsaicin-mediated vasodilation in the pig nasal mucosa and reduces the integrated and duration-based capsaicin- and CGRP-mediated skin vasodilation responses, confirming it acts as a functional CGRP receptor antagonist in vivo^[2].