Bradykinin (1-5) is a major stable metabolite of Bradykinin, formed by the proteolytic action of angiotensin-converting enzyme (ACE).The bradykinin (BK) fragment (1-5) (RPPGF) is among the most stable of naturally occurring metabolites. Bradykinin (1-5) may be used as a marker for BK production in vivo.

Lys-Bradykinin acetate is an endogenous bradykinin receptor agonist.

Peptide antagonist of the B2 bradykinin receptor (pKi = 10.3); conformationally constrained cyclized analog of HOE 140. Blocks hypotension and bronchoconstriction in vivo. Displays selectivity for B2 over 29 other receptors and ion channels (pIC50 < 5.5).