The kallikrein-kinin system is falling into pieces: bradykinin fragments are biological active peptides
Igor Maciel Souza-Silva,
Cristiane Amorim de Paula,
Robson A S Santos,
Vívian Louise Soares de Oliveira,
Isabella Domingos da Rocha,
Maísa Mota Antunes,
Lídia Pereira Barbosa Cordeiro,
Vanessa Pereira Teixeira,
Sérgio Ricardo Aluotto Scalzo Júnior,
Flávio Almeida Amaral,
Jarbas Magalhães Resende,
Marco Antônio Peliky Fontes,
Gustavo Batista Menezes,
Posted 14 Sep 2020
bioRxiv DOI: 10.1101/2020.09.14.296004
Posted 14 Sep 2020
Background and purpose Bradykinin [BK-(1-9)] is an endogenous peptide involved in many physiological and pathological processes, such as cardiovascular homeostasis and inflammation. The central dogma of the kallikrein-kinin system is that BK-(1-9) fragments are biologically inactive. In this manuscript, we proposed to test whether these fragments were indeed inactive. Experimental Approach Nitric oxide (NO) was quantified in human, mouse and rat cells loaded with DAF-FM after stimulation with BK-(1-9), BK-(1-7), BK-(1-5) and BK-(1-3). We used adult male rat aortic ring preparation to test vascular reactivity mediated by BK-(1-9) fragments. Changes in blood pressure and heart rate was measured in conscious adult male rats by intraarterial catheter method. Key results BK-(1-9) induced NO production in all cell types tested by B2 receptor activation. BK-(1-7), BK-(1-5) and BK-(1-3) also induced NO production in all tested cell types but this response was independent of the activation of B1 receptor and/or B2 receptor. BK-(1-7), BK-(1-5) or BK-(1-3) induced only vasorelaxant effect and in a concentration-dependent fashion. Vasorelaxant effects for BK-(1-7), BK-(1-5) or BK-(1-3) were independent of the kinin receptors. Different administration routes ( i.e ., intravenous or intra-arterial) did not affect the observed hypotension induced by BK-(1-7), BK-(1-5) or BK-(1-3). Importantly, these observations diverged from the BK-(1-9) results, highlighting that indeed the BK-(1-9) fragments do not seem to act via the classical kinin receptors. Conclusions and implications In conclusion, BK-(1-7), BK-(1-5) and BK-(1-3) are biologically active components of the kallikrein-kinin system. Importantly, observed pathophysiological outcomes of these peptides are independent of B1R and/or B2R activation. ### Competing Interest Statement The authors have declared no competing interest.
- Downloaded 122 times
- Download rankings, all-time:
- Site-wide: 117,452
- In pharmacology and toxicology: 958
- Year to date:
- Site-wide: 108,660
- Since beginning of last month:
- Site-wide: None
Downloads over time
Distribution of downloads per paper, site-wide
- 27 Nov 2020: The website and API now include results pulled from medRxiv as well as bioRxiv.
- 18 Dec 2019: We're pleased to announce PanLingua, a new tool that enables you to search for machine-translated bioRxiv preprints using more than 100 different languages.
- 21 May 2019: PLOS Biology has published a community page about Rxivist.org and its design.
- 10 May 2019: The paper analyzing the Rxivist dataset has been published at eLife.
- 1 Mar 2019: We now have summary statistics about bioRxiv downloads and submissions.
- 8 Feb 2019: Data from Altmetric is now available on the Rxivist details page for every preprint. Look for the "donut" under the download metrics.
- 30 Jan 2019: preLights has featured the Rxivist preprint and written about our findings.
- 22 Jan 2019: Nature just published an article about Rxivist and our data.
- 13 Jan 2019: The Rxivist preprint is live!