[The influence of 1-DOPA on emotional responses and serotonin metabolism in the rat brain].

Experiments were conducted on male Wistar rats. Intraperitoneal injection of 1-DOPA (.100 - 200 mg/kg increased the brain concentration of dopamine and homovanilinic acid and lowered the level of brain serotonin, with simultaneous elevation of its metabolite 5-HIAA. A decrease in serotonin level was accompanied by increased emotional reactivity and agressiveness in rats. L-DOPA (100 mg/kg) decreased the binding of serotonin formed from tryptophane (100 mg/kg), accelerating its catabolism in the brain; at the same time 1-DOPA eliminated the depressive action of tryptophane on the emotional reactivity and aggressiveness. It is supposed that increased emotional excitation elicited by 1-DOPA was partially mediated through the block of the serotoninergic system.