Effect of DL-erythro-dihydroxyphenylserine on the locomotor activity of the mouse

Effect of dihydroxyphenylserine (DOPS) on the locomotor activity of mice pretreated with beta-phenylisopropylhydrazine was studied using an Animex activity meter. An intraperitoneal injection of DL-erythro-DOPS (200 mg/kg) suppressed significantly the locomotor stimulation by the MAO inhibitor, while DL-threo-DOPS (200 mg/kg) had no effect. Only slight suppression was observed after the administration of 100 mg/kg of DL-erythro-DOPS. Effect of DOPS on the concentrations of brain catecholamines and serotonin of mice pretreated with the MAO inhibitor was also analysed. The administration of DL-erythro-DOPS significantly increased the concentration of noradrenaline, while DL-threo-DOPS did not affect the contents of brain amines in the experimental condition. The suppressive effect of DL-erythro-DOPS on the locomotor stimulation by the MAO inhibitor was confirmed by a simultaneous administration of the amino acid and d-phenylisopropylmethylamine to mice. Based on these findings, the neural mechanisms of the locomotor activity and a clinical application of DL-erythro-DOPS to the manic syndrome were discussed.