ON MECHANISM OF 5-HYDROXYTRYPTAMINE RELEASE BY THYMOLEPTICS

Rabbits were treated with nialamide followed by chlorimipramine, imipramine, desipramine or amitriptyline. Cortical brain slices were prepared and incubated with Krebs‐Henseleit solution. Release of 5‐hydroxytryptamine (5‐ht) into the incubation medium was measured. Chlorimipramine, imipramine and amitriptyline caused release of 5‐ht, whereas desipramine was without effect. The ability of cortical brain slices to retain 5‐ht was dependent on energy supply, involving both aerobic and anaerobic metabolism. The data support the view that the antidepressant drugs block the membrane pump of 5‐ht neurons. The observations also indicate that 5‐ht is involved in thermoregulation. 1969 Royal Pharmaceutical Society of Great Britain