Low Platelet Monoamine Oxidase Activity Research Articles

A correlation between platelet monoamine oxidase activity and plasma prolactin concentrations in man.

Increases in plasma prolactin concentrations produced by alpha-methyl-p-tyrosine, a catecholamine synthesis inhibitor, varied inversely with baseline platelet monoamine oxidase activity in 12 patients with chronic schizophrenia. In normal volunteers with low monoamine oxidase activity and in unmedicated patients with chronic schizophrenia, plasma prolactin concentrations varied directly with platelet monoamine oxidase activity. No such relationship was found in normal subjects with high platelet monoamine oxidase activity. These data suggest that platelet monoamine oxidase activity reflects monoaminergic activity in the tubero-infundibular system, which in turn affects plasma prolactin concentrations. This relationship may be important in patients with low platelet monoamine oxidase activity, such as some chronic schizophrenics.

Platelet Mao Activity and Evoked Potentials in the Identification of Subjects Biologically at Risk for Psychiatric Disorders

Individuals potentially at risk for psychiatric disorders were identified by screening 375 college student volunteers for low platelet monoamine oxidase (MAO) activity levels. The lower and upper 10% in MAO activity were administered a personal and family history interview, psychological tests and average evoked response (AER) electroencephalographic procedures. Results indicated that low MAO males and females were socially more active, had more psychiatric contact, and had relatives who were psychiatrically more disturbed than high MAO subjects. Low MAO males had more convictions, experimented more with illegal drugs and had elevated scores on the MMPI. AER criteria further defined a high risk group of low MAO-AER augmenters which had more suicides among their relatives and higher scores on the schizophrenia scale of the MMPI.

Platelet Monoamine Oxidase Activity in Schizophrenia: A Review of the Data

The authors review studies of platelet and white cell monoamine oxidase (MAO) activity in schizophrenic patients. The data on acute schizophrenic patients remain inconclusive. Review of 26 reports of chronic schizophrenic patients leaves little doubt, however, that there is a subgroup in which the enzyme activity is decreased. Despite the strong association of decreased MAO activity and chronic schizophrenia, the etiological relationship of low platelet MAO activity to schizophrenia has not been demonstrated. More complete diagnostic descriptions will shed light on precisely which patients have lowered MAO activity. Further metabolic investigations with such patients are needed to determine the physiological significance of this phenomenon.

Platelet aggregation and chlorpromazine therapy.

British Journal of Clinical PharmacologyVolume 6, Issue 6 p. 538-540 Free Access Platelet aggregation and chlorpromazine therapy. DJ Boullin, DJ BoullinSearch for more papers by this authorJM Know, JM KnowSearch for more papers by this authorJR Peters, JR PetersSearch for more papers by this authorMW Orr, MW OrrSearch for more papers by this authorMG Gelder, MG GelderSearch for more papers by this authorDG Grahame-Smith, DG Grahame-SmithSearch for more papers by this author DJ Boullin, DJ BoullinSearch for more papers by this authorJM Know, JM KnowSearch for more papers by this authorJR Peters, JR PetersSearch for more papers by this authorMW Orr, MW OrrSearch for more papers by this authorMG Gelder, MG GelderSearch for more papers by this authorDG Grahame-Smith, DG Grahame-SmithSearch for more papers by this author First published: December 1978 https://doi.org/10.1111/j.1365-2125.1978.tb00881.xCitations: 20AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat References Ball, S.E., Boullin, D.J. & Glenton, P.A.M. (1977). Interactions between noradrenaline and 5-hydroxytryptamine involving platelet aggregation. J. Physiol., 272, 98– 99P. Benedict, C.R. & Grahame-Smith, D.G. (1978). Plasma noradrenaline and adrenaline concentrations and dopamine-β-hydroxylase activity in patients with shock due to septicaemia, trauma and haemorrhage. Quart. J. Med., New Series 47, 185, 1– 20. Boullin, D.J. & Glenton, P.A.M. (1978) Characterisation of receptors mediating 5-hydroxytryptamine and catecholamine-induced platelet aggregation, assessed by the actions of α and β blockers, butyrophenones, 5-HT antagonists and chlorpromazine. Br. J. Pharmac., 62, 537– 542. Boullin, D.J. & Grimes, R.P.J. (1976). Increased platelet aggregation in patients receiving chlorpromazine: responses to 5-hydroxytryptamine, dopamine and N-dimethyldopamine. Br. J. clin. Pharmac., 3, 649– 654. Boullin, D.J., Orr, M.W. & Peters, J.R. (1978). The platelet as a model for investigating the clinical efficacy of centrally acting drugs: relations between platelet aggregation and clinical condition in patients treated with chlorpromazine. In Platelets: A Multidisciplinary Approach, eds G.S. Gaetano & S. Garattini, New York: Raven Press, (in press). Boullin, D.J., Woods, H.F., Grimes, R.P.J., Grahame-Smith, D.G., Wiles, D., Gelder, M.G. & Kolakowska, T. (1975). Increased platelet aggregation responses to 5-hydroxytryptamine in patients taking chlorpromazine. Br. J. clin. Pharmac., 2, 29– 35. Buchsbaum, M.S., Coursey, R.D. & Murphy, D.L. (1976). The biochemical high risk paradigm: behavioural and familial correlates of low platelet monoamine oxidase activity. Science, 194, 339– 341. Mills, D.C.B. & Roberts, G.C.K.(1967). Membrane active drugs and the aggregation of human blood platelets. Nature, 213, 35– 38. Orr, M.W. & Boullin, D.J. (1976). The relationship between changes in 5-HT induced platelet aggregation and clinical state in patients treated with fluphenazine. Br. J. clin. Pharmac., 3, 925– 928. Pletscher, A. (1978). Platelets as models for monoaminergic neurones. In Essays in Neurochemistry and Neuropharmacology, M.B.H. Youdim, W. Lovenberg, D.F. Sharman and J.R. Lagnado eds, pp. 49– 101. Chichester: Wiley. Citing Literature Volume6, Issue6December 1978Pages 538-540 ReferencesRelatedInformation

Platelet monoamine oxidase and serum dopamine-beta-hydroxylase activity in chronic alcoholics.

Previous independent reports suggest that low platelet monoamine oxidase (MAO) activity and high serum dopamine-beta-hydroxylase (DBH) activity may be associated with alcoholism or vulnerability toward alcoholism. However, there are also contradictory reports in the literature with regard to each of these two enzymes. We measured both platelet MAO and serum DBH activity in alcoholics followed up at periodic intervals for 12 months after hospitalization for acute alcoholism. Platelet MAO activity in the alcoholics was significantly lower compared to that of nonpsychiatric controls throughout the 12-month period, whereas serum DBH activity in the alcoholics was essentially the same as control values. Thus, low platelet MAO activity, previously reported in a spectrum of clinical psychiatric disorders, appears to be a relatively stable phenomenon in chronic alcoholics irrespective of acute intoxication or pathophysiological factors associated with acute decompensation in individuals vulnerable to alcoholism.

Low platelet monoamine oxidase activity and chronic marijuana use

Mean platelet monoamine oxidase (MAO) activity in 26 consecutively-studied male marijuana smokers was significantly lower than in a comparable group of non-marijuana smoking males. In addition, the level of current marijuana use reported by the subjects was significantly and inversely correlated with MAO activity. No acute reduction in MAO activity was found in response to smoking a marijuana cigarette containing 15 mg of delta-9-THC. Significant in vitro inhibition of MAO activity by THC was detected only at THC concentrations above 10 −5M, approximately 100 times the peak plasma concentrations seen in vivo following smoking.

Psychological correlates of monoamine oxidase activity in normals.

This study replicates and extends earlier work by finding that low levels of platelet monoamine oxidase (MAO) activity correlate with sensation seeking, high ego strength, positive affect, and high leisure time activity levels, somewhat similar psychological correlates also being found for plasma amine oxidase activity. Although there are several ways in which a schizophrenia/MAO relationship may exist and still be congruent with the present data, these results pose difficulties for theories which link low MAO activity levels specifically to schizophrenia. Nothing in the present findings, however, is incongruent with the possibility of an association between low platelet MAO activity and bipolar affective disorder.

The biochemical high-risk paradigm: behavioral and familial correlates of low platelet monoamine oxidase activity.

A population of individuals potentially at risk for psychiatric disorders was identified by screening 375 college student volunteers for low platelet monoamine oxidase (MAO) activity levels. The lower and upper 10 per cent in MAO activity were interviewed and family history data were obtained. Low-MAO probands reported more frequent psychiatric or psychological counseling and problems with the law. Families of low MAO probands had an eightfold increase in the incidence of suicide or suicide attempts over those of high-MAO probands. This suggests that reduced MAO levels, reported previously in patients with affective disorders and chronic schizophrenia, may predict a vulnerability to psychiatric disorder.