Sarpogrelate, a Selective 5-HT2A Serotonergic Receptor Antagonist, Inhibits Serotonin-Induced Coronary Artery Spasm in a Porcine Model

Abstract

Serotonin is one of the most important vasoactive substances and has been implicated in the pathogenesis of coronary artery spasm and of acute coronary syndrome. We have recently demonstrated that local and long-term treatment with interleukin-1beta(IL-1beta) causes coronary arteriosclerotic changes and hyperconstrictive responses to serotonin in pigs in vivo. However, it remains to be examined which serotonergic (5-HT) receptor subtype mediates coronary spasm and whether alterations in serotonergic receptors are involved in the abnormality. In this study, we examined the inhibitory effect of sarpogrelate, a selective 5-HT2A serotonergic receptor antagonist, on the serotonin-induced coronary spasm as well as the possible alterations of serotonergic receptors in our porcine model. A segment of the porcine coronary artery was carefully dissected and aseptically wrapped with cotton mesh absorbing IL-1beta-bound microbeads from the adventitia. Two weeks after the procedure, angiographic study was performed, followed by binding assay for 5-HT1B and 5-HT2A serotonergic receptors and reverse transcription-polymerase chain reaction (RT-PCR) analysis for mRNA of those receptors. Angiographic study showed coronary vasospastic responses to serotonin at the IL-1beta-treated site. Sarpogrelate dose-dependently inhibited the serotonin-induced coronary spasm, but it did not affect the prostaglandin F2alpha-induced vasoconstriction. Radiolabeled receptor-binding assay showed that receptor affinity or receptor number of the 5-HT1B, or 5-HT2A receptors did not differ significantly between the spastic and the control sites. Furthermore, RT-PCR analysis showed that the expression of neither 5-HT2A nor 5-HT1B receptor mRNA was significantly altered at the spastic site. These results indicate that serotonin-induced coronary spasm is mediated primarily by 5-HT2A receptor in our porcine model, although the 5-HT2A receptor was not up-regulated, suggesting that alteration in the signal-transduction pathway for vascular smooth muscle contraction beyond the 5-HT2A receptor plays a primary role in the pathogenesis of coronary spasm in our porcine model.

Site-Directed Mutagenesis of the Serotonin 5-Hydroxytryptamine2C Receptor: Identification of Amino Acids Responsible for Sarpogrelate Binding

“…5) It inhibits thrombus formation, 6,7) lowers platelet aggregation, 8,9) inhibits both serotonin-induced coronary artery spasm, 10) and contraction 11) in porcine model as well as vascular smooth muscle cell proliferation. 12) Presently these pathophysiological effects are claimed to be mediated by 5-HT 2A receptors.…”

Inhibition of 5‐Hydroxytryptamine Receptor 2B Reduced Vascular Restenosis and Mitigated the β‐Arrestin2–Mammalian Target of Rapamycin/p70S6K Pathway

“…In a porcine model, sarpogrelate inhibited 5‐HT–induced coronary contraction and spam 54, 55. Sarpogrelate ameliorated the progression of atherosclerosis, reduced intimal hyperplasia in vein graft, and inhibited thrombus formation on neointima in rabbit models 56, 57, 58.…”

Associated Factors of Anxiety among Acute Coronary Syndrome Patients in Kelantan and Terengganu

“…In atherosclerotic arteries, however, damage to the endothelium prevents the release of nitric oxide with the result that serotonin leads to vasoconstriction (28). So, it is not surprising that elevated blood serotonin levels have been associated with IHD and cardiac events (29). The patients with phobic anxiety have then been found to have abnormalities in the coagulation and fibrinolytic system leading to a hypercoagulable state (30).…”