Abstract
We studied the effects of phenothiazine neuroleptics on cell shape and osmotic resistance of human erythrocytes. All of the neuroleptics tested induced cell shape change of the internalization type, due to membrane invagination, and also gave two-phasic effects on the osmotic behaviour of the cells, with a protective effect on hypotonic hemolysis in relatively low concentrations and a stimulative effect in higher concentrations. Both effects were exerted almost immediately upon contact of the cells with the drugs and were dependent on drugconcentrations. The effects on cell shape were independent of temperature while the protective effects on osmotic resistance were slightly temperature-dependent, being weaker at temperatures lower than 37°. Both effects increased in the order of diethazine, promethazine, chlorpromazine, perazine, prochlorperazine and trifluoperazine. A non-phenothiazine drug, amitriptyline, also showed similar effects, in a comparative intensity as diethazine.