Effects of clozapine on cerebral catecholaminergic neurone systems.

1. Clozapine, a dibenzodiazepine derivative claimed to possess antipsychotic properties in man without producing extrapyramidal disorders, greatly increased the turnover of cerebral dopamine in the rat.2. The drug itself was virtually devoid of cataleptigenic activity in rats; however, it antagonized prochlorperazine-induced catalepsy.3. It is proposed that clozapine causes a blockade of striatal dopamine receptors which is of the surmountable type in contrast to that produced by cataleptigenic neuroleptics. In addition, clozapine may also increase the turnover of cerebral noradrenaline.