生物活性

• 描述Calpain is a Ca²⁺-mediated cytosolic cyctein protease existed in various cells. Calpeptin is a potent calpain inhibitor with ID₅₀ values of 52 nM, 34 nM, 138 nM, and 40 nM for Calpain I (porcine erythrocytes), Calpain II (porcine kidney), Papain, and Calpain I (human platelets), respectively. In platelets stimulated by A₂₃₁₈₇, 66% of ABP and 69% of P235 remained undegraded in the presence of 10μg/mL calpeptin, in comparison to 26% of ABP and 40% of P235 remained without calpeptin. The activity of intrinsic calpain in platelets was completely abolished by the treatment of 100μg/mL calpeptin. Calpeptin at the concentration of 34nM reduced calpain activity by 44% in the homogenate of proliferating PC12 cells. When PCI2 cells were incubated with NGF and 36μM calpeptin for 17h, the probabilities for a PCI2 cell to extend a given maximal neurite length were increased as compared to non-calpeptin-treated cells. In a murine model of middle cerebral artery occlusion, the intra-cerebroventricle injection of calpeptin (50μg dissolved in 5μL DMSO) before the occlusion resulted in a significant reduction of neuronal apoptosis in hippocampal CA1 sector, as compared to DMSO-treated animals, via the inhibition of caspase-3 expression.

• 动物研究
  剂量	Mice: 10 mg/kg[3] (i.p.)
  给药途径	i.p.