Cell experiment:

Cardiomyocytes from mice are pre-incubated with Rimacalib (10 μM) for at least 15 min by including the dye in the loading buffer for Ca2+-fluorescent dyes or by pre-incubation in experimental solution for 15 min (patch-clamp experiments)[1].

Rimacalib is a Ca2+/calmodulin-dependent protein kinase II (CaMKII) inhibitor, with IC50s of ~1 μM for CaMKIIα to ~30 μM for CaMKIIγ.

Rimacalib (SMP-114) improves (by ~40%) Ca2+-transient potentiation during the 30 s stimulation pause, higher Fura-2 transient amplitude after the pause upon Rimacalib vs. 37.2±4.3% in control, n=60/17 cells/mice vs. n=65/17, p<0.05) and in parallel cardiomyocyte contractility (135.0±15.4% vs. 97.2±16% increase of twitch amplitude, p=0.098)[1].

[1]. Neef S, et al. Reduction of SR Ca2+ leak and arrhythmogenic cellular correlates by SMP-114, a novel CaMKII inhibitor with oral bioavailability. Basic Res Cardiol. 2017 Jul;112(4):45.