CP-339818

CP-339818 is a non-peptide Kv1.3 channel (IC₅₀ = 200 nM) and Kv1.4 channel blocker. CP 339818 inhibits HCN channel with IC₅₀s of 18.9 μM and 43.4 μM against HCN1 and HCN4 (high Cl^-). CP-339818 has significantly weaker blocking effects on Kv1.1, Kv1.2, Kv1.5, Kv1.6, Kv3.1-4, and Kv4.2 channels. CP-339818 selectively blocked Kv1.3, thereby inhibiting the activation process of human T cells. CP-339818 can be used to study the physiological functions of HCN and Kv channels^[1][2][3]. In Vitro:CP-339818 suppresses human T cell activation, suggesting that blockade of Kv1.3 alone is sufficient to inhibit this process^[1].
CP-339818 (5 μM) effectively block the remaining outward potassium current in Kv2.1^⁻/⁻ β cells, and does not significantly enhance glucose-stimulated insulin secretion (GSIS)^[2].
CP-339818 (0-100 μM)'s inhibitory effect on HCN1 and HCN4 in low-concentration of Cl^- internal solution is weakened with IC₅₀ of 26.2 and > 100 μM, , and this blocking effect is also voltage-dependent (the higher the voltage, the stronger the blocking effect)^[3].