Role of surface activity in mechanism of actions of tricyclic antidepressants

The role of surface activity has been studied in the mechanism of action of tricyclic antidepressants (TCAs). TCAs have been shown to generate liquid membranes in series with a supporting membrane by the virtue of their amphiphillicity. Transport of important biogenic amines (adrenaline, nor-adrenaline, dopamine and 5-hydroxy tryptamine) and ions (potassium, sodium and calcium) have been studied in the presence of liquid membranes generated by surface-active TCAs. The data on the modifications in the permeability of important biogenic amines and ions indicates that the liquid membranes generated by TCAs may play a significant role in the mechanism of their anti depressant action. The surface-active nature of the drugs has been discussed with relevance to their pharmacological effects.