PB1126 - Inhibition of the coagulation pathways by Nitroxyl (HNO)

Tuesday, June 25, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Co-Author(s)

RG

Ricardo M. Gomez

Researcher
Institute of Biotechnology and Molecular Biology, UNLP-CONICET, La Plata, Argentina
CABA, Ciudad Autonoma de Buenos Aires, Argentina

Co-Author(s)

GM

Gala Minsky

Student
Institute of Experimental Medicine, National Academy of Medicine-CONICET
CIUDAD DE BUENOS AIRES, Ciudad Autonoma de Buenos Aires, Argentina
SK

Santiago Klajnberg

Student
Laboratory of Experimental Thrombosis and Immunobiology of Inflammation, IMEX-CONICET, National Academy of Medicine, Buenos Aires, Argentina
Ciudad de Buenos Aires, Ciudad Autonoma de Buenos Aires, Argentina
FD

Fabio Doctorovich

Researcher
INQUIMAE, Faculty of Exact and Natural Sciences, University of Buenos Aires, C.A.B.A. Argentina.
CIUDAD AUTONOMA BUENOS AIRES, Ciudad Autonoma de Buenos Aires, Argentina

Presenting Author(s)

Mirta Schattner, PhD

Director
Laboratory of Experimental Thrombosis and Immunobiology of Inflammation, IMEX-CONICET, National Academy of Medicine, Buenos Aires, Argentina.
Ciudad Autónoma de Buenos Aires, Ciudad Autonoma de Buenos Aires, Argentina

Co-Author(s)

RP

Roberto G. Pozner

Associate Researcher
Institute of Experimental Medicine, National Academy of Medicine-CONICET
CIUDAD AUTONOMA BUENOS AIRES, Ciudad Autonoma de Buenos Aires, Argentina

Background: The one-electron reduced and protonated form of NO•, nitroxyl anion (HNO), is increasingly recognized as a novel entity with distinct pharmacology and potential therapeutic advantages over nitric oxide in several cardiovascular diseases including heart failure. The role of this gas mediator on the coagulation system has not yet been investigated.

Aims: To investigate the role of HNO on the in vitro coagulation process.

Methods: Angeli´s salt (AS) was used as a HNO donor. Citrated blood (WB) was obtained from healthy donors and platelet-rich or poor plasma (PRP or PPP) were obtained by differential blood centrifugation. The Lee–White clotting time and clot retraction assays were done with venous blood placed into a glass tube without anticoagulants. Activated partial thromboplastin time (aPTT) and prothrombin time (PT) were performed to evaluate the effect of AS on the intrinsic and extrinsic coagulation pathways.

Results: The HNO donor significantly prolonged the clotting time in a concentration-dependent manner and accordingly, the presence of AS impaired clot retraction (Figure A-B). Evaluation of the effect of AS on clotting time in WB, PRP, and PPP after recalcification revealed that a higher AS concentration was required to prolong the clotting time of recalcified WB than PRP, and PPP suggesting that platelets may consume some of the HNO released by AS (Figure C). PPP was the biological sample most sensitive to the inhibition of HNO. aPTT and PT assays were significantly prolonged in the presence of AS indicating that coagulation inhibition occurred at the level of the common pathway (Figure D).

Conclusion(s): These data show that HNO delays coagulation by affecting the common pathway. Together with the previously described inhibitory effect of HNO on endothelial cells, platelets and monocytes, our results suggest that HNO donors are indeed promising drugs for the treatment of cardiovascular diseases.