Inhibition by trifluoperazine and digitonin of several forms of pinocytosis.
The effect of the calmodulin antagonist trifluoperazine on fluid phase, adsorptive and receptor-mediated pinocytosis in cultured human fibroblasts and mouse peritoneal macrophages was studied. Uptake in each case was reversibly inhibited by about 20% without toxic effects. Low concentrations of the detergent digitonin had a similar effect. Thus the three uptake mechanisms have common features, and we suggest that in both fibroblasts and macrophages they may reflect uptake within vesicles participating in receptor-mediated endocytosis. These effects of trifluoperazine may operate directly on membranes without the participation of calmodulin.
D000818:Animals; D002147:Calmodulin / Q000502:physiology; D004072:Digitonin / Q000494:pharmacology*; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D010873:Pinocytosis / Q000187:drug effects*; D014268:Trifluoperazine / Q000494:pharmacology*
D002147:Calmodulin; D014268:Trifluoperazine; D004072:Digitonin