SKA-121 is a selective KCa3.1 activator (EC50s: 109 nM and 4.4 μM for KCa3.1 and KCa2.3, respectively).

KCa3.1:（EC50）109 nM, KCa2.3:4.4 μM（EC50）

SKA-121 is a typical positive-gating modulator and shifts the calcium-concentration response curve of KCa3.1 to the left. SKA-121 shows 41-fold selectivity for KCa3.1 (EC50 109 nM±14 nM) over KCa2.3 (EC50 4.4 ± 1.6 μM). SKA-121 is 200- to 400-fold selective over representative KV (KV1.3, KV2.1, KV3.1, and KV11.1), NaV (NaV1.2, NaV1.4, NaV1.5, and NaV1.7), as well as CaV1.2 channels [1].

SKA-121 is relatively well soluble (logP=1.79) and can potentially be added to drinking water in animal experiments, it orally is also administered, and find that it has an oral availability of roughly 25%. SKA-121 has a short half-life (~20 minutes), and plasma decay is extremely rapid (21.3±2.4 μM at 5 minutes; 483±231 nM at 1 hour and 53±44 nM at 4 hours). SKA-121 can be used as a new KCa3.1 selective pharmacological tool compound despite its relatively short half-life in mice. SKA-121 (100 mg/kg i.p.) significantly lowers mean arterial blood pressure in normotensive and hypertensive wild-type but not in KCa3.1-/- mice in blood pressure telemetry experiments. A lower dose of SKA-121(30 mg/kg) does not produce significant alterations in the MAP [1].