[Prolonged administration of antidepressants induces changes in the pulsed release but not in the reverse uptake of biogenic amines].

The experiments on rats have shown that antidepressant concentrations that cause 50% inhibition of 14C-NA and 3H-HT uptake by brain slices remain unchanged following prolonged administration of antidepressants (imipramine, pirazidole, harmane and its derivatives--C-153, C-307, C-394, C-395), as compared to the control. Electrical stimulation of brain slices upon long-term treatment of rats with antidepressants and preincubation with 14C-NA and 3H-HT enhanced presynaptic release of radioactive mark at concentrations of antidepressants (EC2) 3-14 times lower than those in the control animals. Long-term antidepressant administration reduces the inhibitory influence of clonidine and HT on presynaptic release of 14C-NA and 3H-HT by brain slices. It is suggested that long-term administration of antidepressants decreases the sensitivity of terminal axons of NA- and HT-ergic neurons to autoinhibitory effect of neurotransmitter release.