Vanillins relax isolated porcine coronary arterial smooth muscle by inhibiting L‐type Ca2+ channels (LB574)

Abstract

Vanillin (VA) and vanillyl alcohol (VAA) are major components of natural vanilla, while ethyl vanillin (EtVA) is a synthetic vanillin analog with antioxidant and anti‐inflammatory properties. This study compared the relaxing effect of vanillins (VA, VAA, EtVA) and poly(vanillin) oxalate (PVO) nanoparticles (Ø 260nm) containing VA in porcine coronary artery rings by measuring isometric tension. Vanillins but not PVO caused concentration‐dependent, endothelium‐independent and complete relaxations during contractions to U46619, KCl or endothelin‐1 with an order of potency of VAA<VA<EtVA. The relaxations of U46619 contracted preparations were unaffected by inhibitors of NOS (L‐NAME), cyclooxygenases (indomethacin), soluble guanylyl cyclase (ODQ), KCa (TRAM‐34, UCL‐1684, iberiotoxin), KATP (glibenclamide), Kir (BaCl2), and TRPV3 channels (camphor) or by antioxidants (catalase, apocynin, tempol, N‐acetylcysteine, tiron). Vanillins inhibited contractions induced by both Ca2+ reintroduction in 40mM KCl solution and BayK8644. Both VA and PVOs caused partial relaxation of XO/XOD contracted rings. In conclusion, relaxation to vanillin(s) is solely due to the inhibition of L‐type Ca2+ channels in porcine coronary arteries. Both VA and PVO can prevent contractions induced by superoxide anions, and thus could be used to relieve coronary vasospasm associated with elevated oxidative stress.Grant Funding Source: Supported by Brain Korea 21 PLUS Project, NRF and NRF‐2012M3A9C6050204