RED-BLOOD-CELL MEMBRANE DYNAMICS IN SCHIZOPHRENIA .1. MEMBRANE FLUIDITY

Using the fluorescent probe DPH (1,6-diphenyl-1,3,5-hexatriene), stead y-state anisotropy (r(s)) values were determined in red blood cell (RB C) ghost membranes of schizophrenic patients before (n = 26) and after (n = 16) haloperidol withdrawal, and age- and sex-matched normal cont rols (n = 22). Patients on haloperidol were treated with doses between 5 and 20 mg/day for at least 5 weeks. Drug-free patients had been fre e of all psychotropic medication for an average of 36 days. The mean r (s) value of haloperidol-treated patients (0.2422+/-0.0076) was not si gnificantly different from that of either the drug-free patients (0.24 45+/-0.0092) or the normal controls (0.2383+/-0.0083). A significant i ncrease (p = 0.037) in r(s) values, however, was observed in the drug- free schizophrenic patients as compared to that of the controls. Furth ermore, the mean r(s) values of relapsed drug-free patients were signi ficantly (p < 0.05) higher than in the same individuals on haloperidol treatment. Changes in r(s) values of drug-free patients were also sig nificantly correlated with their increase in psychosis ratings (r = 0. 74, p = 0.001). The 'structural order' of RBC ghost membrane, however, was not correlated with age, age of onset, daily haloperidol dose, pl asma haloperidol levels, plasma cholesterol concentrations, or the dur ation of illness, haloperidol treatment or drug-free period. Thus, the present data demonstrate that RBC membrane fluidity is not affected b y haloperidol treatment. Following haloperidol withdrawal, however, th ose patients with decreased RBC membrane fluidity, which correlated wi th increased psychosis, may be prone to relapse within 6 weeks.