Involvement of benzodiazepine receptors in the mechanism of anxiolytic action of the synthetic analogue of the terminal fragment of neuropeptide Y

Abstract

The aim of study – to reveal the possible involvement of benzodiazepine receptors in the anxiolytic effect of a new modified analogue of neuropeptide Y – nonapeptide NP9.
The experiment was performed on 43 white nonlinear mice weighing 25–30 g using the «Elevated plus maze» test. Nonapeptide NP9 was аdministeredintranasally at a dose of 0.2 mg/kg. The reference drug was Semax (Peptogen, Russia) at a dose of 0.1 mg/kg intranasally. To study the possible involvement of the GABAA-receptor complex in the NP9 mechanism of action was used a selective antagonist of benzodiazepine receptors – flumazenil 15 mg/kg intraperitoneally.
Nonapeptide NP9 reduced the anxiety of animals in the «Elevated plus maze» test, but when combined with flumazenil the markers of anxiolytic activity decreased to the control level and were significantly inferior to the indicators of the effect of NP9 per se. Semax did not show anti-anxiety activity, and flumazenil did not affect its behavioural effects.
Thus, benzodiazepine receptors are involved in the mechanism of the anxiolytic action of nonapeptide NP9.