NNC 55-0396 is a selective inhibitor of T-type calcium channels that blocks Cav3.1 in stably expressing HEK293 cells (IC50 = 6.8 μM) with no discernible effect on high voltage-activated (L-type) channels in INS-1 cells up to a concentration of 100 μM. NNC 55-0396 suppresses tremor in two murine models, the GABAA α1-null (20 mg/kg) and harmaline-induced (12.5 mg/kg) tremor models, and was better tolerated than mibefradil . In arterial smooth muscle cells, NCC 55-0396 (IC50 = 80 nM) inhibits voltage-dependent K+ channels but does not affect their voltage sensitivity. NNC 55-0396 (1-5 μM) also suppresses angiogenesis in vitro by inhibiting hypoxia-inducible factor-1α activity, and it slows tumor growth of flank xenografts of U87MG cells in mice when administered at 20 mg/kg.
