Effects of tricyclic and tetracyclic antidepressants on the three subtypes of GABA transporter.

We examined the effects of 11 antidepressants on the activities of three-rat GABA transporters (GAT1, GAT2 and GAT3) expressed in COS-7 cells. Desipramine and maprotiline inhibited all subtypes of GABA transporter, while doxepin, mianserin, trimipramine, nortriptyline and amitriptyline inhibited certain types of GABA transporters. Amitriptyline inhibited the GAT1 and GAT3 at the reasonable dosage for clinical administration. These results suggest that the inhibition of GABA uptake might have some role in the prescribed antidepressive and sedative nature of this drug.