Kinetics of the interaction of sertraline with the human platelet plasma membrane 5-hydroxytryptamine carrier.

Sertraline, a new selective 5-HT uptake inhibitor showed a mixed pattern of inhibition of human platelet 5-HT uptake with a Ki value of 2.5 nM and K'i value of 25 nM. Imipramine and alaproclate were found to be fully competitive inhibitors of 5-HT uptake with Ki values of 8 and 130 nM respectively. Sertraline was a fully competitive inhibitor of high-affinity [3H]imipramine binding to platelet membranes with a Ki value of 1.3 nM, as was alaproclate and 5-HT with Ki values of 170 and 800 nM respectively. Both sertraline and imipramine, at a concentration of 10 microM caused a fast monophasic dissociation of [3H]imipramine from platelet membranes in contrast to serotonin which caused a slow monophasic dissociation.