Inhibition of platelet functions and thrombosis through selective or nonselective inhibition of the platelet P2 receptors with increasing doses of NF449 [4,4',4'',4'''-(carbonylbis(imino-5,1,3-benzenetriylbis-(carbonylimino)))tetrakis-benzene-1,3-disulfonic acid octasodium salt].

Abstract

Our aim was to determine whether the newly described P2X1 antagonist NF449 [4,4',4'',4'''-(carbonylbis(imino-5,1,3-benzenetriylbis(carbonylimino)))tetrakis-benzene-1,3-disulfonic acid octasodium salt] could selectively antagonize the platelet P2X1 receptor and how it affected platelet function. NF449 inhibited alpha,beta-methyleneadenosine 5'-triphosphate-induced shape change (IC50 = 83 +/- 13 nM; n = 3) and calcium influx (pA2 = 7.2 +/- 0.1; n = 3) (pIC50 = 6.95) in washed human platelets treated with apyrase to prevent desensitization of the P2X1 receptor. NF449 also antagonized the calcium rise mediated by the P2Y1 receptor, but with lower potency (IC50 = 5.8 +/- 2.2 microM; n = 3). In contrast, it was a very weak antagonist of the P2Y12-mediated inhibition of adenylyl cyclase activity. Selective blockade of the P2X1 receptor with NF449 led to reduced collagen-induced aggregation, confirming a role of this receptor in platelet activation induced by collagen. Intravenous injection of 10 mg/kg NF449 into mice resulted in selective inhibition of the P2X1 receptor and decreased intravascular platelet aggregation in a model of systemic thromboembolism (35 +/- 4 versus 51 +/- 3%) (P = 0.0061; n = 10) but without prolongation of the bleeding time (106 +/- 16 versus 78 +/- 7 s; n = 10) (N.S.; P = 0.1209). At a higher dose (50 mg/kg), NF449 inhibited the three platelet P2 receptors. This led to a further reduction in platelet consumption compared with mice injected with saline (13 +/- 4 versus 42 +/- 3%) (P = 0.0002; n = 5). NF449 also reduced dose-dependently the size of thrombi formed after laser-induced injury of mesenteric arterioles. Overall, our results indicate that NF449 constitutes a new tool to investigate the functions of the P2X1 receptor and could be a starting compound in the search for new antithrombotic drugs targeting the platelet P2 receptors.

• Authors: Béatrice Hechler, Stéphanie Magnenat, Maddalena L Zighetti, Matthias U Kassack, Heiko Ullmann, Jean-Pierre Cazenave, Richard Evans, Marco Cattaneo, Christian Gachet
• Journal: The Journal of pharmacology and experimental therapeutics (J Pharmacol Exp Ther) Vol. 314 Issue 1 Pg. 232-43 (Jul 2005) ISSN: 0022-3565 [Print] United States
• PMID: 15792995 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 4,4,',4'',4'''-(carbonylbis(imino-5,1,3-benzenetriylbis(carbonylimino)))tetrakis(benzene-1,3-disulfonate)
• Benzenesulfonates
• Fibrinolytic Agents
• Platelet Aggregation Inhibitors
• Receptors, Purinergic P2
• Receptors, Purinergic P2X
• Adenosine Diphosphate
• Adenosine Triphosphate
• Collagen
• Adenylyl Cyclases
• alpha,beta-methyleneadenosine 5'-triphosphate
• Calcium
• Epinephrine

Topics

• Adenosine Diphosphate (pharmacology)
• Adenosine Triphosphate (analogs & derivatives, pharmacology)
• Adenylyl Cyclases (metabolism)
• Animals
• Benzenesulfonates (administration & dosage, pharmacology)
• Bleeding Time
• Blood Platelets (drug effects)
• Calcium (metabolism)
• Collagen (pharmacology)
• Dose-Response Relationship, Drug
• Epinephrine (pharmacology)
• Fibrinolytic Agents
• Humans
• In Vitro Techniques
• Injections, Intravenous
• Mice
• Microscopy, Electron, Scanning
• Oocytes (metabolism)
• Platelet Aggregation (drug effects)
• Platelet Aggregation Inhibitors (administration & dosage, pharmacology)
• Platelet Function Tests
• Receptors, Purinergic P2 (drug effects)
• Receptors, Purinergic P2X
• Thromboembolism (prevention & control)
• Thrombosis (drug therapy)
• Xenopus laevis