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.