Evaluation of Noopept Effect on the Neurotransmitter Amino Acids in the Hippocampus in Alcohol Drinking Rats Using in Vivo Microdialysis

Abstract

The aim of the present work was to study the dynamics of neurotransmitter amino acids after acute Noopept (a dipeptide analogue of piracetam used in clinical practice as a nootropic agent) administration in intact and long-term ethanol (ETOH) exposed rats. Albino male rats were given 10% (vol/vol) ETOH solution as the only source of fluid 24 h / 7 days per week (n = 5). Also we used intact rats of the same age which had no access to ethanol (n = 5). The excitatory and inhibitory amino acids in the extracellular space of the dorsal hippocampus region in freely moving intact and ETOH-exposed rats during prolonged alcohol deprivation were measured using the intracerebral microdialysis method followed by HPLC/ED. There were no significant differences in the level of neurotransmitter amino acids between ETOH-exposed and intact animals. For the first time, in vivo experiments the effect of Noopept (1.5 mg/kg, i.p.) on the level of excitatory amino acids (an increase in ASP by 2.38 times and GLU by 2.28 times) along with an increase in the level of the inhibitory amino acid GLI by 3.13 times only in intact rats was shown. Thus, in ETOH-exposed rats under the adaptive rearrangements in prolonged ethanol withdrawal, the neurochemical mechanisms of the hippocampus seem to be characterized by insensitivity to an acute Noopept administration. Animal neurochemical studies of changes in the mediator amino acids due to the long-term effect of alcohol on the CNS may be of practical importance for the development of optimal strategies and pharmacotherapy.