Cyclo (His-Pro) potentiates GABA/ethanol-mediated chloride uptake by neurosynaptosomes.

Cyclo (His-Pro) CHP is a cyclic dipeptide endogenous to the brain of a variety of animal species including man. Administration of exogenous peptide to rodents has been shown to exhibit a variety of biologic activities including, modification of pharmacologic actions of alcohol. Since there are many apparent similarities between the actions of GABA and CHP in modulating alcohol pharmacology, we have examined whether CHP can modulate alcohol potentiation of GABA-receptor-mediated 36Cl-influx in neurosynaptosomes. The results show a further dose-dependent potentiation of 36Cl-influx in neurosynaptosomes by CHP in the presence of GABA and alcohol.