Biochem/physiol Actions

(Pyr1)-Apelin-13, the major apelin form in human plasma and heart, corresponds to Apelin-13 with posttranslationally modified pyroglutamyl (pGlu, pE) at the N-terminus instead of glutamine (Gln, Q). (Pyr1)-Apelin-13 exhibits higher APJ agonist potency than Apelin-13 (EC50 = 0.30 vs. 0.37 nM, respectively; acidification induction in human APJ-expresing CHO cell cultures). (Pyr1)-Apelin-13 is reactive toward human, murine, rat, and bovine species, and widely used for studyinhg APJ-mediated cellular and physiological functions both in cultures and in animals in vivo (via intraperitoneal, intravenous, intrathecal injection).