Platelet Monoamine Oxidase Activity in Schizophrenia

1979 ◽  
Vol 134 (4) ◽  
pp. 366-371 ◽  
Author(s):  
John Mann ◽  
K. M. Thomas
Keyword(s):  
Monoamine Oxidase ◽  
Normal Subjects ◽  
Control Groups ◽  
Platelet Mao ◽  
Duration Of Illness ◽  
Before And After ◽  
Mao Activity ◽  
Platelet Mao Activity ◽  
Platelet Monoamine Oxidase ◽  
Institutionalized Patients

SummaryA study was made of platelet monoamine oxidase (MAO) activity in non-medicated, newly-admitted schizophrenics and institutionalized chronic schizophrenics both on and off medication. These patients were compared to two control groups: normal subjects and brain-damaged institutionalized patients. No relationship was found between platelet MAO activity and the severity or duration of illness, duration of psychotropic medication, presence of auditory hallucinations or institutionalization. Mean platelet MAO activity did not differ significantly between the schizophrenic subgroups and control groups. Thirty-one patients studied before and after treatment with phenothiazines showed no significant change in platelet MAO activity. The findings did not indicate a relationship between schizophrenia, its treatment or outcome and platelet MAO activity.

Platelet Monoamine Oxidase and Epinephrine-Induced Platelet Aggregation

1978 ◽  
Vol 40 (01) ◽  
pp. 037-042 ◽  
Author(s):  
Ennio C Rossi ◽  
Gerlinde Louis ◽  
Martha Bieber ◽  
E Albert Zeller
Keyword(s):  
Platelet Aggregation ◽  
Monoamine Oxidase ◽  
Normal Subjects ◽  
Human Platelets ◽  
Aggregation Response ◽  
Platelet Mao ◽  
Mao Activity ◽  
Platelet Mao Activity ◽  
Platelet Monoamine Oxidase ◽  
Induced Aggregation

SummaryPlatelet MAO activity and the aggregation response to epinephrine, ADP, and collagen were measured in normal subjects. There was a direct correlation between the amount of platelet MAO activity and the per cent aggregation induced by 1 and 2 μM epinephrine. There were lesser correlations between platelet MAO and ADP or collagen-induced aggregation. These findings suggest that platelet MAO may play a role in determining the response of human platelets to epinephrine.

Platelet monoamine oxidase activity and life stress as predictors of psychopathology and coping in a community sample

1989 ◽  
Vol 19 (1) ◽  
pp. 79-90 ◽  
Author(s):  
Joanne Boyd Irving ◽  
Robert D. Coursey ◽  
Monte S. Buchsbaum ◽  
Dennis L. Murphy
Keyword(s):  
Monoamine Oxidase ◽  
Mental Health Professionals ◽  
Life Stress ◽  
Stressful Life Events ◽  
Community Sample ◽  
Adult Males ◽  
Platelet Mao ◽  
Mao Activity ◽  
Platelet Mao Activity ◽  
Platelet Monoamine Oxidase

SynopsisThe present study, using a diathesis-stress model, attempted to confirm prior findings with platelet monoamine oxidase (MAO) activity and stress in a middle-aged, non-clinic population. One hundred and seventy-eight adult males from a statewide community club were tested for platelet MAO activity and stressful life events and were also given a variety of psychological measures of both psychopathology and psychosocial coping. The data were examined both for correlations across the total sample and for a comparison of high-risk groups (top and bottom 15% of MAO activity) with a middle MAO group. Low platelet MAO activity was related to a higher incidence of contact with mental health professionals, and more frequent use of alcohol and cigarette smoking. High MAO activity was related to higher levels of anxiety and somatization. High levels of stress were related to increased psychosocial problems reported for female and family members, higher scores on two schizophrenia-related MMPI scales (schizophrenia and paranoia subscales), but fewer idiosyncratic associations, elevated hypomanic, depression, and anxiety scores, increased alcohol use, and increased use of prescribed antianxiety and sedative medication. Neither MAO nor stress were related to current levels of psychosocial coping. Moreover, no interaction effects were uncovered for MAO activity and stress combined.

Kinetics and Thermolability of Platelet Monoamine Oxidase in Cluster Headache and Migraine

Cephalalgia ◽  
1984 ◽  
Vol 4 (2) ◽  
pp. 125-134 ◽  
Author(s):  
Elisabet Waldenlind ◽  
Jan Sääf ◽  
Karl Ekbom ◽  
Svante Ross ◽  
Lars-Olof Wahlund ◽  
...  
Keyword(s):  
Monoamine Oxidase ◽  
Cluster Headache ◽  
Control Group ◽  
Enzyme Properties ◽  
Headache Disorders ◽  
Platelet Mao ◽  
Mao Activity ◽  
Platelet Mao Activity ◽  
Platelet Monoamine Oxidase ◽  
C 30

Platelet monoamine oxidase activity (MAO) from 33 cluster headache patients (17 males, 16 females) and 34 migraine patients (16 males, 18 females) was assayed. The kinetic constants (apparent V max and apparent K m ) and the thermolability, measured as the ratio of the platelet MAO activity after and before heat treatment (+52°C, 30 min), were determined. The MAO activity and V max values were significantly lower in cluster headache than in migraine and in both headache disorders compared to a control group (62 males, 66 females). When comparing all groups, K m was not significantly different except for migraine females, who had lower K m values compared to control females. Thermolability was significantly higher in cluster headache than in migraine and in both headache disorders compared to the control group. Smokers of five cigarettes or more per day had significantly lower Vmax values but similar K m and thermolability values compared to those smoking less or nothing. The findings of low maximal velocities and high thermolability of platelet MAO in cluster headache and migraine are suggested to represent constitutionally different enzyme properties.

Genetics of Platelet MAO Activity in Discordant Schizophrenic and Normal Twins

1983 ◽  
Vol 142 (6) ◽  
pp. 560-565 ◽  
Author(s):  
Michael A. Reveley ◽  
Adrianne M. Reveley ◽  
Christine A. Clifford ◽  
Robin M. Murray
Keyword(s):  
Monoamine Oxidase ◽  
Genetic Control ◽  
Platelet Mao ◽  
Mao Activity ◽  
Platelet Mao Activity ◽  
Platelet Monoamine Oxidase ◽  
The Mean ◽  
Mz Twins ◽  
Age And Sex

SummaryPlatelet monoamine oxidase (MAO) activity was compared in four age and sex-matched groups: monozygotic (MZ) twins discordant for schizophrenia, normal MZ twins, normal dizygotic (DZ) twins and unrelated individuals. Among the twin groups, schizophrenic and normal, there was a remarkably consistent degree of genetic control amounting to 70–80 per cent of the variation in activity. The mean platelet MAO activity of the schizophrenic twins was significantly lower than that of controls, but not than that of their psychiatrically well, neuroleptic-free cotwins; indeed the correlation for the MZ twins discordant for schizophrenia was almost exactly the same as that for the normal MZs. Thus, lower platelet MAO activity in schizophrenia, where it is found, is genetically modulated and not the result of the illness or its treatment.

Low Platelet Monoamine Oxidase Activity in Sensation-Seeking Bullfighters

CNS Spectrums ◽  
1999 ◽  
Vol 4 (12) ◽  
pp. 21-24 ◽  
Author(s):  
José Luis Carrasco ◽  
Jerónimo Sáiz-Ruiz ◽  
Marina Díaz-Marsá ◽  
Jesús César ◽  
Juan José López-Ibor
Keyword(s):  
Monoamine Oxidase ◽  
Sensation Seeking ◽  
Behavioral Pattern ◽  
Control Group ◽  
Platelet Mao ◽  
Isotopic Methods ◽  
Healthy Control ◽  
Mao Activity ◽  
Platelet Mao Activity ◽  
Platelet Monoamine Oxidase

AbstractIn this study, we attempt to demonstrate an association between low platelet monoamine oxidase (MAO) activity, as assessed by isotopic methods, and the stable behavioral pattern of sensation- and risk-seeking of professional bull-fighters. Sixteen professional bullfighters were studied and compared with a control group of 46 healthy control subjects who did not engage in risky jobs or activities. The group of bullfighters had significantly reduced platelet MAO activity compared with the control group (P<0.05). Bullfighters were shown to be significantly more extroverted and sensation-seeking than controls on various temperament scales. A predisposition to engage in risky activities (eg, bullfighting) and sensation-seeking could be partly conditioned by the presence of biological components of personality manifested by a significantly decreased platelet MAO activity.

The Effect of Lithium on Platelet Monoamine Oxidase Activity in Bipolar and Schizoaffective Disorders

1982 ◽  
Vol 140 (2) ◽  
pp. 192-198 ◽  
Author(s):  
Herbert Y. Meltzer ◽  
Patricia Tueting ◽  
Herbert Jackmann
Keyword(s):  
Monoamine Oxidase ◽  
Rating Scale ◽  
Lithium Treatment ◽  
Lithium Carbonate ◽  
Global Assessment Scale ◽  
Platelet Mao ◽  
Mao Activity ◽  
Platelet Mao Activity ◽  
Platelet Monoamine Oxidase ◽  
Psychiatric Rating Scale

SummaryPlatelet monoamine oxidase (MAO) activity was studied in 33 in-patients with bipolar and schizoaffective disorder who were treated with lithium. Platelet MAO activity was found to increase following 10–41 days of lithium treatment compared to a prior drug free period, and the increase was positively correlated with the duration of lithium treatment. The increase in platelet MAO activity was not correlated with clinical improvement as measured by the Brief Psychiatric Rating Scale (BPRS) and the Global Assessment Scale (GAS). The number of platelets per unit of blood was also significantly correlated with the number of days of lithium treatment. However, the increase in the number of platelets in lithium-treated patients was not correlated with the increase in MAO activity and thus appears not to account for it. These results indicate that studies relating platelet MAO activity to psychiatric diagnosis should be interpreted cautiously if patients are receiving lithium carbonate.

Platelet monoamine oxidase activity in obsessive-compulsive disorder

2007 ◽  
Vol 22 (8) ◽  
pp. 525-529 ◽  
Author(s):  
Manuel Arrojo ◽  
Enrique Baca-Garcia ◽  
Maria Mercedes Perez-Rodriguez ◽  
Helen Dolengevich-Segal ◽  
Mercedes Navio-Acosta ◽  
...  
Keyword(s):  
Monoamine Oxidase ◽  
Obsessive Compulsive Disorder ◽  
Healthy Controls ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
Platelet Mao ◽  
Biological Studies ◽  
Mao Activity ◽  
Platelet Mao Activity ◽  
Platelet Monoamine Oxidase

AbstractResponse to SSRIs suggests the implication of the serotonergic system in obsessive-compulsive disorder (OCD). However, biological studies on serotonergic function in OCD have yielded contradictory results. Platelet monoamine oxidase (MAO) activity has been proposed as an index of cerebral serotonin activity.The aim of this study was to examine platelet MAO activity in 29 OCD patients and 29 healthy controls matched by age, sex and tobacco use. We also explored the relationship between platelet MAO activity and aggressive obsessions in OCD patients.There were no differences in platelet MAO activity between OCD patients and healthy controls. We found a significant correlation between platelet MAO activity and Y-BOCS scores in the group of patients with Y-BOCS scores >15.OCD patients with aggressive obsessions had significantly lower levels of platelet MAO activity than patients without aggressive obsessions.Our results suggest that platelet MAO activity may be a marker of OCD severity, and that low platelet MAO activity may be associated with aggressive obsessions in OCD patients.

Platelet Monoamine Oxidase Activity in Acute Schizophrenia: Relationship to Symptomatology and Neuroleptic Medication

1981 ◽  
Vol 139 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Frank Owen ◽  
Rachel C. Bourne ◽  
Timothy J. Crow ◽  
Eve C. Johnstone ◽  
Adnam A. Fadhli
Keyword(s):  
Enzyme Activity ◽  
Negative Symptoms ◽  
Thought Disorder ◽  
Neuroleptic Drugs ◽  
Monoamine Oxidase Activity ◽  
Platelet Mao ◽  
Mao Activity ◽  
Platelet Mao Activity ◽  
Platelet Monoamine Oxidase ◽  
Reduced Activity

SummaryPlatelet MAO activity was assessed in 35 schizophrenics during a trial of the isomers of flupenthixol. Enzyme activity was unrelated to severity of symptoms, the presence of delusions, hallucinations or thought disorder or to negative symptoms. In a few patients MAO activity fluctuated widely with time, but in the group of patients on medication there was a slow decrease in enzyme activity which was significant after 28 days of treatment. Enzyme activity after 14 days' drug treatment was still correlated with activity before treatment, but after 28 days this significant correlation disappeared. Slow effects of neuroleptic drugs on platelet MAO activity may explain previous findings of reduced activity of the enzyme in schizophrenia.

Monoamine oxidase: associations with alcohol dependence, smoking and other measures of psychopathology

2000 ◽  
Vol 30 (2) ◽  
pp. 443-454 ◽  
Author(s):  
J. B. WHITFIELD ◽  
D. PANG ◽  
K. K. BUCHOLZ ◽  
P. A. F. MADDEN ◽  
A. C. HEATH ◽  
...  
Keyword(s):  
Alcohol Use ◽  
Panic Disorder ◽  
Monoamine Oxidase ◽  
Conduct Disorder ◽  
Alcohol Dependence ◽  
Social Phobia ◽  
Platelet Mao ◽  
Mao Activity ◽  
Platelet Mao Activity ◽  
The Difference

Background. Many reports have appeared on associations between platelet monoamine oxidase (MAO) activity and susceptibility to psychiatric conditions; principally alcohol dependence but also conduct disorder, other drug use and depression. Recently, it has become apparent that MAO activity is inhibited by some component of cigarette smoke, and smokers have low platelet MAO activity. Since the prevalence of smoking is higher in many of the conditions in which MAO has been implicated, the MAO susceptibility associations may be partly, or entirely, false.Methods. We have measured platelet MAO in 1551 subjects, recruited from the Australian NHMRC Twin Registry, who have provided information on alcohol use and dependence, smoking, conduct disorder, depression, attempted suicide, panic disorder and social phobia.Results. Current smoking reduced platelet MAO activity in a significant and dose-related manner, with no evidence of lower MAO in ex-smokers or in non-smoking subjects with co-twins who smoked. Alcohol use and lifetime DSM-III-R alcohol dependence history were not associated with MAO activity when smoking was taken into account. Depression, panic disorder and social phobia showed no significant associations with platelet MAO activity. Subjects with a history of serious attempts at suicide had low platelet MAO activity; but although the difference from controls was as great as the reduction associated with smoking it was not significant after correction for smoking effects.Conclusions. Although synaptic MAO activity undoubtedly plays a role in psychopathology, the concept that platelet MAO activity is a direct genetic marker of vulnerability to alcohol dependence cannot be sustained.

Altered platelet monoamine oxidase activity in affective disorders

1979 ◽  
Vol 9 (4) ◽  
pp. 729-736 ◽  
Author(s):  
John Mann
Keyword(s):  
Affective Disorders ◽  
Lithium Carbonate ◽  
Depressive Illness ◽  
Reactive Depression ◽  
Platelet Mao ◽  
Genetic Mechanisms ◽  
Mao Activity ◽  
Platelet Mao Activity ◽  
Platelet Monoamine Oxidase ◽  
Bipolar Patients

SYNOPSISPlatelet MAO activity was found to be elevated in primary depressive illness, and the severity to correlate positively with MAO activity. The reactive depression subgroup's mean platelet MAO activity was not significantly different from that of the controls. The endogenous group's unipolar and bipolar subgroups had significantly different platelet MAO activity, respectively high and low. The differences in MAO activity between unipolar and bipolar patients appeared to persist in the well state, but not after lithium carbonate therapy. These differences in MAO activity were apparent with the substrate tyramine but not with benzylamine. Altered MAO activity in patients with affective disorders may be determined through genetic mechanisms.

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