Bradykinin Peptides

Bradykinin is a peptide that causes blood vessels to dilate (enlarge), and therefore causes blood pressure to lower. A class of drugs called ACE inhibitors, which are used to lower blood pressure, increase bradykinin (by inhibiting its degradation) further lowering blood pressure. Bradykinin works on blood vessels through the release of prostacyclin, nitric oxide, and Endothelium-Derived Hyperpolarizing Factor.

Bradykinin is a physiologically and pharmacologically active peptide of the kinin group of proteins, consisting of nine amino acids.

Bradykinin is a potent endothelium-dependent vasodilator, causes contraction of non-vascular smooth muscle, increases vascular permeability and also is involved in the mechanism of pain. Bradykinin also causes natriuresis, contributing to a drop in blood pressure.

Bradykinin raises internal calcium levels in neocortical astrocytes causing them to release glutamate.

Bradykinin is also thought to be the cause of the dry cough in some patients on angiotensin converting enzyme (ACE) inhibitor drugs. This refractory cough is a common cause for stopping ACE inhibitor therapy. In which case Angiotensin II Receptor Antagonists are the next line of treatment.

Overactivation of bradykinin is thought to play a role in a rare disease called Hereditary Angioedema, formerly known as Hereditary Angio-Neurotic Edema.

Initial secretion of Bradykinin post-natally causes constriction and eventual atrophy of the ductus arteriosus, forming the ligamentum artertiosum between the pulmonary trunk and aortic arch.