α-CGRP (rat) (trifluoroacetate salt)

α-Calcitonin gene-related peptide (α-CGRP) is a neuropeptide with roles in vasodilation, cardiovascular regulation, and inflammation. It belongs to the calcitonin family of peptides, which also includes amylin , calcitonin , and adrenomedullin. α-CGRP binds selectively to heterotrimeric complexes of calcitonin receptor-like receptor (CRLR) and receptor activity-modifying proteins RAMP 1 or 3 (RAMP1 and 3; IC50s = 7 and 23 nM, respectively) over a complex of CLCR and RAMP2 (IC50 = >1,000 nM). It binds to rat brain and spleen membrane preparations (IC50s = 3.9 and 3.5 nM, respectively) and relaxes human cerebral and middle meningeal arterial segments precontracted with prostaglandin F2α . In vivo, α-CGRP (0.01-3,000 ng/kg) decreases mean arterial blood pressure (MABP) and increases pial arteriole (PA) and middle meningeal artery (MMA) diameters in rats with closed cranial windows. It induces a 50% increase in diameter of arterioles precontracted with human endothelin-1 in vivo in hamster cheek pouch at a concentration of 39.8 pM.