title: Effect of SEA0400, a novel inhibitor of sodium-calcium exchanger, on myocardial ionic currents.
abstract: The effects of 2-[4-[(2,5-difluorophenyl) methoxy]phenoxy]-5-ethoxyaniline (SEA0400), a newly synthesized Na(+)-Ca(2+) exchanger (NCX) inhibitor, on the NCX current and other membrane currents were examined in isolated guinea-pig ventricular myocytes and compared with those of 2-[2-[4-(4-nitrobenzyloxy) phenyl]ethyl]isothiourea (KB-R7943). SEA0400 concentration-dependently inhibited the NCX current with a 10 fold higher potency than that of KB-R7943; 1 microM SEA0400 and 10 microM KB-R7943 inhibited the NCX current by more than 80%. KB-R7943, at 10 microM, inhibited the sodium current, L-type calcium current, delayed rectifier potassium current and inwardly rectifying potassium current by more than 50%, but SEA0400 (1 microM) had no significant effect on these currents. These results indicate that SEA0400 is a potent and highly selective inhibitor of NCX, and would be a powerful tool for further studies on the role of NCX in the heart and the therapeutic potential of its inhibition.
authors.affiliation: Department of Pharmacology, Toho University School of Pharmaceutical Sciences, Funabashi, Chiba 274-8510, Japan.
authors.forename: Hikaru
authors.initials: H
authors.lastname: Tanaka
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Nishimaru
authors.forename: Tokiko
authors.initials: T
authors.lastname: Aikawa
authors.forename: Wataru
authors.initials: W
authors.lastname: Hirayama
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Koki
authors.initials: K
authors.lastname: Shigenobu
mesh_terms: D000814:Aniline Compounds / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D006352:Heart Ventricles / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D007473:Ion Channels / Q000378:metabolism; D017136:Ion Transport / Q000187:drug effects; D008297:Male; D010647:Phenyl Ethers / Q000494:pharmacology*; D012964:Sodium / Q000378:metabolism*; D019831:Sodium-Calcium Exchanger / Q000037:antagonists & inhibitors*; D013890:Thiourea / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: C101670:2-(2-(4-(4-nitrobenzyloxy)phenyl)ethyl)isothiourea methanesulfonate; D000814:Aniline Compounds; D007473:Ion Channels; D010647:Phenyl Ethers; C430918:SEA 0400; D019831:Sodium-Calcium Exchanger; D012964:Sodium; D013890:Thiourea; D002118:Calcium