Application Calpain inhibitor I reversibly blocks the calcium-dependent neutral cysteine protease calpain I. Calpains have been implicated in various cellular processes, including cell proliferation, apoptosis, and cell differentiation. Biochem/physiol Actions Can initiate apoptosis in HL-60 cells1 but blocks dexamethasone-induced apoptosis in thymocytes and cycloheximide-induced apoptosis in metamyelocytes.2 Inhibits cyclin B degradation and arrests the cell cycle at G1/S and at meta-/anaphase.3 Blocks induction of nitric oxide synthase by LPS in macrophages.4
