piperidines and tryptamine-4-5-dione

Tryptamine-4,5-dione (4,5-DKT) a neurotoxic derivative of serotonin (5-HT), was injected into the lateral ventricle of the rat in order to evaluate its biochemical effects. The levels of 8 substances in the hippocampus, striatum and prefrontal cortex were examined 3, 7 and 14 days after treatment with 4,5-DKT. 5-Hydroxytryptamine and 5-hydroxyindoleacetic acid (5-HIAA) levels were decreased in all three regions by days 7 and 14, respectively. Tryptamine-4,5-dione had no significant effect on dopaminergic or adrenergic systems or on the levels of L-tryptophan and L-tyrosine, in any of the three areas of brain examined. Reduced activity of tryptophan hydroxylase in the cortex was observed 14 days after administration of 4,5-DKT. However, administration of 4,5-DKT did not alter the binding of [3H]paroxetine, a specific antagonist of the uptake of 5-HT, to nerve terminals. These results indicate that 4,5-DKT produced depletion of 5-HT without eliminating serotoninergic nerve terminals.

Topics: Animals; Brain Chemistry; Cerebral Cortex; Electrochemistry; Hydroxyindoleacetic Acid; In Vitro Techniques; Indolequinones; Injections, Intraventricular; Male; Membranes; Neurotransmitter Agents; Paroxetine; Piperidines; Rats; Rats, Inbred Strains; Serotonin; Serotonin Antagonists; Tryptamines; Tryptophan Hydroxylase