Lys-(des-Arg9, Leu8)-Bradykinin trifluoroacetate salt is a peptide chain containing nine amino acids. The amino acid sequence of bradykinin is Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg (RPPGFSPFR). Bradykinin is a peptide that causes blood vessels to dilate, thus resulting in lower blood pressure. A class of drugs used to lower blood pressure called ACE inhibitors lower blood pressure by increasing the concentration of bradykinin (by inhibiting its degradation). Bradykinin acts on blood vessels by releasing prostacyclin, nitric oxide, and endothelial-derived hyperpolarizing factors.