[Action of triftazin on the physicochemical properties and the membrane proton pump of the synaptic vesicles in the rat brain].

The effects of trifluoperazine (TFP) on some membrane processes were studied in the isolated rat brain synaptic vesicles (SV). TFP (10(-5)-10(-4) M) was found to cause a sharp rise in the intensity of light scattering by SV suspension which was due both to an increased vesicle aggregation and to changes in the refraction index of the membrane. In addition, TFP blocked the ATP-dependent proton transport into the vesicles (K0.5 = 10(-6) M) with the concomitant stimulation of the ATPase activity which suggests an uncoupling effect caused by the permeation of this weak base through the membrane and subsequent protonation in an acid interior medium resulting in the elimination of a proton gradient. Thus, the neuroleptic drug--TFP has various effects on membrane processes which are apparently unrelated to its recognized role as a calmodulin antagonist.