PAMP-12 (human, mouse, rat, porcine, bovine) (trifluoroacetate salt)

Proadrenomedullin N-terminal 12 peptide (PAMP-12) is an endogenous peptide fragment found in the adrenal medulla that corresponds to amino acids 9-20 of human PAMP-20 and is involved in potension.^1,2,3 It is an agonist of MAS-related G protein-coupled receptor family member X2 (MRGPRX2).² PAMP-12 inhibits forskolin-induced cAMP accumulation in CHO cells expressing human MRGPRX2 (EC₅₀ = 57.2 nM). It selectively induces calcium mobilization in CHO cells expressing MRGPRX2 (EC₅₀ = 41 nM) over those expressing MRGPRX1, MRGPRX3, or MRGPRX4 at 1 µM. PAMP-12 is an antagonist of nicotinic acetylcholine receptors (nAChRs) that inhibits carbachol-induced catecholamine release (IC₅₀ = 1.3 µM) and calcium and sodium influx (IC₅₀s = 0.39 and 0.87 µM, respectively), but not histamine-induced catecholamine release or calcium and sodium influx (IC₅₀s = >1 µM for all), in primary bovine adrenal chromaffin cells.³ It reduces mean arterial blood pressure in normotensive rats when administered at doses ranging from 10 to 50 nmol/kg.¹