[Effects of new amino acid derivates of dopamine on anxiety-like behavior].

This study was aimed at a comparative analysis of the effects of new amino acid derivatives of dopamine (IEM-2111, IEM-21122, IEM-2123, IEM-2126) on anxiety-like behavior in rats. The behavioral effects of the dopamine-like substances were evaluated under conditions of acute and chronic experiments. In acute experiment, a single dose of substances was administered 45 min prior to the behavioral testing of animals. In chronic experiment, the synthesized compounds were administered in a single daily dose for 14 days. Pharmacological analysis of the effect of drugs was performed in the following doses: 0.1, 1.0, and 10.0 mg/kg (i.p., introduction). Diazepam was used as a reference drug that was introduced in a dose of 1.0 mg/kg (i.p.). The anxiety-like state was determined using the elevated plus maze test, while the behavioral effects were evaluated in the open field test. It was found that IEM-2111, IEM-2122, and IEM-2123 exhibited anxiolytic action under condition of chronic administration, whereas IEM-2126 produced an anxiolytic effect only after acute administration. The introduction of left optical isomers of aromatic or heterocyclic radicals of amino acids into the molecule of 3,4-dimetoxyphenylethylamine results in a more pronounced anxiolytic effect upot chronic administration. The degree of action of the new amino acid derivatives of dopamine has a dose-dependent character, and the maximum effect is manifested at a dose of 1.0 mg/kg.