BIOl.. PSYCHIATRY 1991;30:837-840 837 BRIEF REPORTS Increased Platelet Membrane Lysophosphatidylcholine in Schizophrenia Avdreas M. Pangerl, Andrea Steudle, Hans W. Jaroni, Roderich Riifer, and Wagner F. Gattaz Introduction Disturbances in phospholipid metabolism have been suggested in schizophrenia (Rotrosen and Wolkin 1987; Brody et al 1987). There is in- creasing evidence from numerous studies on blood cells, mostly erythrocytes and platelets, that membrane phospholipid distribution is changed in schizophrenic patients, however, results are not consistent. Some studie.s indicate an increase in phosphatidylserine (PS) but decreases in phosphatidylcholine (PC)~and phosphatidyleth- anolamine (PE) (Steveni# 1972); other studies reported opposite results or no changes at all (Rotrosen and Wolkin 1987). It remains to be clarified whether these discrepancies are due to the investigation of different tissues or to the use of different laboratory procedures. We ~cantly fcmnd a marked difference in the activity, of the phospholipid metabolizing en- zyme phospholipase A2 (PLA2), with signifi- cantly higher levels in plasma, serum, and plate- lets from schizophrenics than in healthy controls or nonschizophrenic psychiatric patiem~ (~Jai,.,: From the Central Institute of Mental Health, Unit Neurobiology of Ftmctior, ai Psychoses, Mannheim, Germany (AMP, AS, WFG); and the Institute of Pharmacology and Toxicology, Faculty of Medicine, Marmheim, University of Heidelberg, Germany (HWJ, RR). Address reprint requests to Prof. Dr. W. F. Gattaz, Central Institute of Mental Health, P.O. Box 12 21 20, 6800 Marm_heim 1, Ger- many. Received February 20, 1991; revised May 20, 1991. et al 1987, 1990a, 1990b). The main substrate of PLA2 is PC, which is degraded into the highly toxic compound lysophosphatidylcholine (LPC) and into arachidonic acid (Chang et al 1987; Irvine 1982). Increased levels of LPC may play an important role in brain function, as LPC changes membrane integrity (van den Bosch 1980) and affects various second messenger sys- tems such as phospholipase C (Carter et al 1990), proteinldnase C (Oishi et al 1990, Nishijima et al 1989), cGMP (Woff et al 1989), Ca2+ levels (Rustenbeck and Lenzen 1989), and neurotrans- miner release (Shigenobu et al 1989). The pur- pose of the present study was *.o investigate the total phospholipid content and the distribution of phospholipids in the platelet membrane of schizophrenics and controls, with a special fo- cus on PC and LPC. Platelets have frequently been used as models for neurons, as both share similar membrane and receptor charac'~ristics (Rotman 1983). Methods The sample comprised nine paranoid schizo- phw.nic patients (three men, six women, mean age 30.1 + 0.5 years, mean duration of the disease 26 _ 11 months, mean +-- SEM) and nine (three men, six womeR) age-matched gen- der-matched healthy controls (mean age 30.3 +-- 1.7 years). Schizophrenic patients were diag- nosed according to DSM-III-R criteria, the psy- @ 1991 Society of Biological Psycl.iatry 0006-3223/911503.50