RS 23597-190 hydrochloride is a potent and selective antagonist of the inositol 1,4,5-trisphosphate (IP₃) receptor (IP₃R). It inhibits IP₃-induced Ca²⁺ release from intracellular stores with high affinity (K_i ~ 5-50 nM), serving as a valuable research tool for studying calcium signaling pathways. Applications include investigations into neuronal excitability, smooth muscle contraction, signal transduction, neurotransmitter release, and cellular processes relevant to neuroscience, cardiology, and oncology.