Some central effects of opipramol given repeatedly.

Some central effects of opipramol administered repeatedly (twice daily, 14 days) were studied in rats and mice. Repeated or acute treatment with opipramol did not change the locomotor activity of rats. Given repeatedly, but not in a single dose, opipramol increased the (+)-amphetamine-induced hyperactivity. The (+)-amphetamine-induced stereotypy was unchanged by acute or repeated treatment with opipramol. The aggressiveness induced by clonidine in mice was attenuated by a single dose of opipramol, but it was markedly enhanced after repeated treatment with this drug. The immobility time of rats (behavioral despair test) was prolonged by a single dose of opipramol; when given three times, opipramol reduced the immobility time. The obtained results seem to indicate that repeated treatment with opipramol leads to similar effects in the experimental models as those after repeated treatment with typical antidepressant drugs, i.e. enhancement of the responses mediated by dopamine receptors (probably in the limbic system, but not in the striatum) and alpha 1-adrenoceptors in the brain.