Neurobiochemical aspects of maprotiline (Ludiomil) action

In the first part of the paper a short review of the neurobiochemical effects of the antidepressant drug maprotiline is given. Its most obvious effect is the inhibition of noradrenaline uptake in peripheral and central neurones. The peculiarity of this action consists in its high degree of selectivity, as no inhibition of serotonin uptake could be demonstrated in vivo. In the second part, the results of new experiments are described. These show that serotonin uptake is not diminished in rat mid-brain synaptosomes even after treatment with very high doses of maprotiline (600 mg/kg p.o.). In addition, the influence of the antidepressant on noradrenaline and serotnin uptake was studied in rat cerebral cortex, cerebellum, hypothalamus and pons-medulla. Dopamine and serotonin uptake were measured in the corpus striatum. Again, only the uptake of noradrenaline was found to be inhibited. There was not even a slight tendency towards inhibition of serotonin uptake. This high degree of selectivity distinguishes maprotiline from the tricyclic antidepressants and thus makes it an intersting 'extreme-type' uptake inhibitor.