INTERACTIONS BETWEEN RESERPINE AND VARIOUS COMPOUNDS ON THE ACCUMULATION OF [C-14] 5-HYDROXYTRYPTAMINE AND [H-3]NORADRENALINE IN HOMOGENATES FROM RAT HYPOTHALAMUS

The effect of reserpine, 5 mg/kg i.p., on the potencies of various compounds in inhibiting the accumulation of [14C] 15-hydroxytryptamine (5-HT) and [3H] (-)-noradrenaline (NA) in synaptosome-rich homogenates from rat hypothalamus was examined. It was found that some compounds, e.g. tryptamine, α-methyltryptamine, (+)-amphetamine and 4-chloroamphetamine, were considerably more potent in inhibiting the 5-HT accumulation in the reserpinized preparation than in the control preparation, whereas other compounds, e.g. chlorimipramine, zimelidine, norzimelidine, fluoxetine, alaproclate and desipramine, had the same activities in the two preparations. The inhibitory potencies of the same compounds on the [3H] NA accumulation was, on the other hand, not influenced by reserpine. The results indicate that tryptamines and amphetamines inhibit the 5-HT accumulation by releasing 5-HT rather than inhibiting its uptake. The same conclusion cannot be drawn for the inhibitors of the NA accumulation. © 1979.