Abstract
Thromboxane A2 (TXA2) is a key mediator of platelet aggregation and smooth muscle contraction. Its action is mediated by its G protein-coupled receptor of which two isoforms, termed TPα and TPβ, occur in humans. TXA2 has been implicated in pathologies such as cardiovascular diseases, pulmonary embolism, atherosclerosis, and asthma. This study describes the pharmacological characterization of BM-613 [N-n-pentyl-N′-[2-(4′-methylphenylamino)-5-nitrobenzenesulfonyl]urea], a new combined TXA2 receptor antagonist and TXA2 synthase inhibitor. It exhibits a strong affinity for human platelet TP receptors (IC50 = 1.4 nM), TPα and TPβ expressed in COS-7 cells (IC50 = 2.1 and 3.1 nM, respectively), and TPs expressed in human coronary artery smooth muscle cells (IC50 = 29 μM). BM-613 shows a weak ability to prevent contraction of isolated rat aorta (ED50 = 1.52 μM) and guinea pig trachea (ED50 = 2.5 μM) induced by TXA2 agonist U-46619 (9.11-dideoxy-9.11-methanoepoxy-prostaglandin F2). Besides, BM-613 antagonizes TPα (IC50 = 0.11 μM) and TPβ (IC50 = 0.17 μM) calcium mobilization induced by U-46619 and inhibits human platelet aggregation induced by U-46619 (ED50 = 0.278 μM), arachidonic acid (ED50 = 0.375 μM), and the second wave of ADP. BM-613 also dose dependently prevents TXA2 production by human platelets (IC50 = 0.15 μM). In a rat model of ferric chloride-induced thrombosis, BM-613 significantly reduces weight of formed thrombus by 79, 49, and 28% at 5, 2, and 1 mg/kg i.v., respectively. In conclusion, BM-613 is a dual and potent TP receptor antagonist and TXA2 synthase inhibitor characterized by a strong antiplatelet and antithrombotic potency. These results suggest that BM-613 could be a potential therapeutic drug for thrombotic disorders.
Footnotes
-
This work was supported by the Fonds National de la Recherche Scientifique and Wellcome Trust. J.H. is funded by the Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture.
-
Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
-
doi:10.1124/jpet.104.079301.
-
ABBREVIATIONS: TXA2, thromboxane A2; AA, amino acid(s); COX, cyclooxygenase; PGH2, prostaglandin endoperoxide H2; TXS, thromboxane synthase; TXRA, thromboxane receptor antagonist; TXSI, thromboxane synthase inhibitor; ASA, acetylsalicylic acid; BM-613, N-n-pentyl-N′-[2-(4′-methylphenylamino)-5-nitrobenzenesulfonyl]urea; BM-573, N-tert-butyl-N′-[2-(4′-methylphenylamino)-5-nitrobenzenesulfonyl]urea; SQ-29548, [1S-[1,2(Z),3,4]]-7-[3-[[2-[(phenylamino)carbonyl]hydrazino]methyl]-7-oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid; U-46619, 9.11-dideoxy-9.11-methanoepoxy-prostaglandinF2; PBS, phosphate-buffered saline; HCASMC, human coronary artery smooth muscle cell; DMSO, dimethyl sulfoxide; PRP, platelet-rich plasma; PPP, platelet-poor plasma; HEK, human embryonic kidney; TXB2, thromboxane B2; S18886, 3-((6R)-6-{[(4-chlorophenyl)sulfonyl]amino}-2-methyl-5,6,7,8 tetrahydro-1-naphthalenyl) propanoic acid, sodium salt.
-
↵1 These authors contributed equally to this work.
- Received October 15, 2004.
- Accepted November 18, 2004.
- The American Society for Pharmacology and Experimental Therapeutics
JPET articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|