VU0134992 hydrochloride is greater than 30-fold selective for Kir4.1 over Kir1.1, Kir2.1, and Kir2.2, is weakly active toward Kir2.3, Kir6.2/SUR1, and Kir7.1, and is equally active toward Kir3.1/3.2, Kir3.1/3.4, and Kir4.2.
The selectivity of VU0134992 hydrochloride for Kir4.1 versus nine other members of the Kir channel family was evaluated at concentrations ranging from 0.3 nM to 30 µM in 11-point CRC experiments, using established Tl+ flux assays. VU0134992 hydrochloride inhibits Kir3.1/Kir3.2 (92% inhibition at 30 µM, IC50=2.5 µM), Kir3.1/Kir3.4 (92% inhibition at 30 µM, IC50=3.1 µM), and Kir4.2 (100% inhibition at 30 µM, IC50=8.1 µM) with approximately the same efficacy and potency that VU0134992 inhibits Kir4.1 (100% at 30 µM, IC50=5.2 µM).