Abstract
Platelet MAO activity was determined, using 14C-tryptamine and 14C-β-phenylethylamine as substrates, in two groups of schizophrenic patients and a normal control population. The first patient group consisted of 75 schizophrenics who had been medication-free for 2 weeks and had not been exposed to neuroleptic drugs for at least 2 months before the off-drug period. The second patient group comprised 55 schizophrenics who were on treatment with haloperidol for at least 2 months.
The enzyme activity was found to be significantly decreased in both drug-free (using only tryptamine as substrate, P<0.05) and haloperidol-treated (P<0.001) chronic schizophrenics as compared with normal controls, and to be significantly lower (P<0.05) in haloperidol-treated than in off-drug chronic schizophrenics. An in vitro study confirmed the lowering effect of haloperidol on MAO activity.
It is suggested that low platelet MAO values observed in chronic schizophrenics might be in part an effect of neuroleptic treatment.
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References
Baezinger NL, Majerus PW (1974) Isolation of human platelets and platelet surface membranes. In: Methods in enzymology, vol 31, part A. Academic, New York San Francisco London, pp 149–155
Berrettini WH, Benfield TC, Schmidt AO, Ladman RK, Vogel WH (1980) Platelet monoamine oxidase in families of chronic schizophrenics. Schizophr Bull 8:235–244
Breier A, Hitzemann RJ, Hirschowitz J, Garver DL (1981) Kinetic analysis of platelet monoamine oxidase in chronic schizophrenia. Life Sci 28:1947–1951
Brockington, I, Crow TJ, Johnstone EC, Owen F (1976) An investigation of platelet monoamine oxidase activity in schizophrenia and schizoaffective psychosis. In: Wolstenholme GEW, Knight J (eds) Monoamine oxidase and its inhibition, Elsevier, New York, pp 353–362
Chojnacki M, Kralik P, Allen RH, Ho BT, Schoolar JC, Smith RC (1981) Neuroleptic-induced decrease in platelet MAO activity of schizophrenic patients. Am J Psychiatry 138:838–840
DeLisi LE, Wise CD, Bridge TP, Rosenblatt JE, Wagner RL, Morihisa J, Karson C, Potkin SG, Wyatt RJ (1981) A probable neuroleptic effect on platelet monoamine oxidase in chronic schizophrenic patients. Psychiatr Res 4:95–107
Harker LA, Finch CA (1969) Thrombokinetics in man. J Clin Invest 48:963–974
Jackman HL, Meltzer HY (1980) Factors affecting determination of platelet monoamine oxidase activity. Schizophr Bull 6:259–265
Leelavathi DE, Smith RC (1980) Chronic neuroleptics and brain monoamine oxidase activity. Biol Psychiatry 15:479–484
Lowry OH, Rosenbrough NJ, Farr AL, Randall RJ (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193:265–275
Murphy DL, Belmaker R, Wyatt RJ (1974) Monoamine oxidase in schizophrenia and other behavioural disorders. J Psychiatr Res 11:221–247
Murphy DL, Wyatt RJ (1972) Reduced platelet monoamine oxidase activity in chronic schizophrenia. Nature 238:225–226
Nies A, Robinson DS, Lamborn K, Lampert RP (1973) Genetic control of platelet and plasma monoamine oxidase activity. Arch Gen Psychiatry 28:834–838
Pisciotta AV, Santos AS, Keller C, Hayes J (1965) Studies on agranulocytosis: The effect of clinical treatment with chloropromazine on nucleic acid synthesis of granulocyte precursors in normal persons. J Lab Clin Med 65:228–235
Robinson DS, Nies A (1980) Demographic biologic, and other variables affecting monoamine oxidase activity. Schizophr Bull 6:298–307
Strahilevitz M, Narasimhachari N, Fischer GW, Meltzer HY, Himwich HE (1975) Indolethylamine-n-methyltransferase activity in psychiatric patients and controls. Biol Psychiatry 10:287–302
Winter H, Herschel M, Propping P, Friedl W, Vogel F (1978) A twin study on three enzymes (DBH, COMT, MAO) of catecholamine metabolism. Correlations with MMPI. Psychopharmacology 57:63–69
Wurtman RJ, Axelrod J (1963) A sensitive and specific assay for the examination of monoamine oxidase. Biochem Pharmacol 12:1439–1441
Wyatt RJ, Murphy DL, Belmaker R, Cohen S, Donnelly CH, Pollin W (1973) Reduced monoamine oxidase in platelets: A possible genetic marker of vulnerability to schizophrenia. Science 179:916–918
Wyatt RJ, Potkin SG, Murphy DL (1979) Platelet monoamine oxidase activity in schizophrenia. A review of the data. Arch Gen Psychiatry 136:377–385
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Del Vecchio, M., Maj, M., D'Ambrosio, A. et al. Low platelet MAO activity in chronic schizophrenics: A long-term effect of neuroleptic treatment?. Psychopharmacology 79, 177–179 (1983). https://doi.org/10.1007/BF00427807
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DOI: https://doi.org/10.1007/BF00427807