Zatebradine(UL-FS49) is a potent HCN channels antagonist, which decreased the heartbeat in a reversible manner; 92% inhibition of the hHCN1-mediated current at 10 uM.IC50 value: 10 uM(92% 92% inhibition of the hHCN1) [1]Target: hHCN channel antagonistThe pharmacological properties of hHCN1-mediated currents resembled those of native hyperpolarization-activated currents (I(h)), that is, blockade by Cs(+) (99% at 5 mm), ZD 7288 (98% at 100 microm) and zatebradine (92% at 10 microm) [1]. When voltage-clamp pulse trains were applied, cilobradine induced a use-dependent blockade of If that was stronger and faster than that with zatebradine. Recovery from blockade during prolonged hyperpolarization was significantly faster with zatebradine [2]. The selective HCN blocker zatebradine reduced the activity of oriens-lacunosum moleculare interneurons in wild-type but not HCN2(-/-) mice and decreased the frequency of spontaneous inhibitory currents in postsynaptic CA1 pyramidal cells [3].

[1]. Gill CH, et al. Characterization of the human HCN1 channel and its inhibition by capsazepine. Br J Pharmacol. 2004 Oct;143(3):411-21. [2]. Van Bogaert PP, et al. Use-dependent blockade of cardiac pacemaker current (If) by cilobradine and zatebradine. Eur J Pharmacol. 2003 Oct 8;478(2-3):161-71. [3]. Matt L, et al. HCN2 channels in local inhibitory interneurons constrain LTP in the hippocampal direct perforant path. Cell Mol Life Sci. 2011 Jan;68(1):125-37.