NEUROLEPTIC PROPERTIES OF RG-TANNIN IN MICE AND RATS

The purpose of the study was to examine the effect of RG-tannin, a new substance of plant origin (purified from rhizoma of Rhea raponticum) with assumed antipsychotic properties in two pharmacodynamic tests: 1/ in yawning behaviour induced with apomorphine or physostigmine in rat s as an indicator of central antidopaminergic effects (in the case of apomorphine) and central anticholinergic effects (in the case of physo stigmine), 2/ in Porsolt forced swimming test in mice (this test is se nsitive to drugs activating or inhibiting central noradrenergic and do paminergic mechanisms). RG-tannin in the dose of 50 mg.kg(-1) (but not 25 mg.kg(-1)) inhibited significantly yawning induced with apomorphin e (0.1 mg.kg), but failed to decrease yawning to a significant extent in rats treated with physostigmine (0.075 mg.kg(-1)). RG-tannin given intraperitoneally in mice in the dose of 25 mg.kg and 50 mg.kg(-1) bod y weight increased statistically significantly the time of immobility in forced swimming test in comparison with mice treated only with sali ne. All these findings indicate that RG-tannin has interesting neurole ptic properties, which could be useful also in veterinary medicine.