Amphetamine-antagonistic property of 4-phenyltetrahydroisoquinoline: effect on noradrenaline release in spinal cord slices.

The amphetamine-related compounds methamphetamine, phenylethylamine and nomifensine increased the K(+)-evoked release of endogenous noradrenaline from rat spinal cord slices. 4-Phenyl-1,2,3,4-tetrahydroisoquinoline (4PTIQ), which alone did not affect the K(+)-evoked release of noradrenaline, inhibited the noradrenaline-releasing effects of methamphetamine, phenylethylamine and nomifensine. 4PTIQ revealed a weak noradrenaline-uptake inhibitory effect, and the effect was weaker than those of desipramine and nomifensine. These results showed that 4PTIQ is an antagonist against the amine-releasing effects of amphetamines.