Effect of some benzamide derivatives on stress-induced behavior and striatum dopamine receptors

The effects of a new benzamide derivative LIS-630 and the well-known neuroleptic, tiapride, were studied on stress-induced hyper- and hypoactive emotional behavioral reaction of animals depending on the individual ability for perceptive-cognitive activity in stress situations, and their affinity to striatal DA receptors. A modified variant of forced swimming method was used. The affinity of the substances to striatal DA receptors was studied by the radioligand binding method using 3H-spiroperidol. The results show that the psychopharmacological profile of LIS-630 differs significantly from the neuroleptic, tiapride. LIS-630 restored escape behavior from stress situation after preliminary exposure of rats to forced swimming and did not disturb escape behavior in animals more resistant to emotional hypoactivity. LIS-630 reduced immobility time at forced swimming. However, it is not effective in preventing hyperemotional reactions induced by L-dopa and stress. The radioligand binding study shows that LIS-630 did not displace 3H-spiroperidol from the binding sites of striatum membranes. The parameters of displacement with tiapride were satisfactory.