5. CONCLUSION
Our study shows that two peptide fragments of BK-(1-9) – BK-(1-7) and
BK-(1-5) – have significant biological activity in human, rat and mouse
cell lines. The cardiovascular response triggered by these fragments
seems to be comparable with that of BK-(1-9). However, these peptides
exhibit significantly less pro-inflammatory responses than those
elicited by BK-(1-9). The observed biological activity for BK-(1-7) and
BK-(1-5) is mediated by receptors other than the canonical kinin
B1 and B2 receptors, implying new
pharmacological target(s) yet to be characterized for this peptide
mediator system. We suggest that the KKS, like the RAS, is now showing
signs of much greater complexity than previously described, in terms of
active components and possible targets. Such changes would allow the KKS
to fine-tune physiological and pathological processes, including those
of the cardiovascular system, inflammation and nociception.