Neuropeptide Cycloprolylglycine Exhibits Neuroprotective Activity after Systemic Administration to Rats with Modeled Incomplete Global Ischemia and in In Vitro Modeled Glutamate Neurotoxicity

We studied cerebroprotective properties of neuropeptide cycloprolylglycine (1 mg/kg) administered intraperitoneally to rats with modeled incomplete global ischemia rats and neuroprotective properties for HT-22 cells under conditions of glutamate toxicity. It was shown that the neuropeptide administered during the postischemic period restored the neurological status of rats by preventing sensorimotor impairments in the limb-placing test and suppression of locomotor activity in the open field test. In in vitro experiments, cycloprolylglycine in concentrations of 10(-5)-10(-8) M exhibited pronounced dose-dependent neuroprotective activity. The results attest to high cerebro- and neuroprotective potential of endogenous peptide cycloprolylglycine.