The effects of protriptyline and clomipramine in vitro on the uptake of 5-hydroxytryptamine and dopamine in human platelet-rich plasma

The effects of protriptyline and clomipramine, at concentrations of 10^-7 M to 10^-4 M, were studied in vitro on the uptake of 5-hydroxytryptamine and dopamine uptake in human platelet-rich plasma. It was found that the tertiary amine, clomipramine, was a more potent inhibitor of 5-hydroxytryptamine uptake than the secondary amine, protriptyline. The activity of both compounds was competitive but it was thought unlikely that they acted through tryptamine receptor sites as methysergide 2.5×10^-8 M had very little effect on 5-hydroxytryptamine uptake. Neither tricyclic antidepressant had any marked effect on dopamine uptake.