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[Investigation of monoamine oxidase gene restriction polymorphism in male populations of the Volga-Ural region].

Restriction polymorphism at the monoamine oxidase A (MAO A) gene was typed in eight male populations of the Volga-Ural region (Bashkirs, Chuvashes, Tatars, Udmurts, Maris, Mordovians, Komis, and Russians inhabiting the Republic of Bashkortostan). Analysis of the MAO A alleles frequency distribution patterns did not reveal statistically significant differences between the Volga-Ural populations examined. The results obtained suggest genetic homogeneity of the populations described in respect of the polymorphic locus examined.

Bashkiria↗

In vitro inhibition of human platelet monoamine oxidase by phenothiazine derivatives.

Nineteen phenothiazines were tested for in vitro inhibition of human platelet type B monoamine oxidase (MAO). The inhibition potency was highly dependent on structures of their side chains. The inhibition was most potent for drugs with (hydroxyethyl-piperazinyl)propyl chains followed in decreasing order by those with (N-methylpiperazinyl)propyl, (2-dimethylamino-2-methyl)ethyl and 3-dimethylaminopropyl chains. Kinetic analyses were carried out for promazine, promethazine, perazine and perphenazine as representatives of each group; the four drugs showed competitive inhibition, and Ki values of 124, 31.4, 19.2 and 22.6 microM, respectively.

Blood Platelets↗

Association of a functional polymorphism of the monoamine oxidase A gene promoter with personality and psychiatric symptoms.

A functional polymorphism in the promoter of the monoamine oxidase gene has recently been described by Sabol et al. This polymorphism is a strong candidate for associations with personality traits and psychiatric symptoms. We report relevant data from a general population sample of 850 Caucasian Australians. We found no associations with anxiety and depression symptoms, with personality traits that predispose to anxiety (neuroticism, behavioral inhibition, negative affect) or to a personality trait related to antisocial behavior (psychoticism).

Adult↗

[Classical monoamine oxidase inhibitor: not registered for, but still a place in the treatment of depression].

In the Netherlands monoamine oxidase (MAO) inhibitors are not registered for the treatment of patients with depression. The classical, nonselective MAO inhibitors--phenelzine and tranylcypromine--are effective but their use is associated with interactions (with tyramine in food, sympathicomimetics and serotonine re-uptake inhibitors) and side-effects (hypertension, hypotension, headache, sleep disturbances and neuromuscular symptoms in particular). Therefore, the classical MAO inhibitors are indicated only in depressive disorders that are unresponsive to the first stages of treatment. Taking this selection into account, treatment should be long-term to avoid relapse.

Depressive Disorder↗

Will amitriptyline prevent the "cheese" reaction of monoamine-oxidase inhibitors?

Administration of amitriptyline greatly diminished the pressor response to intravenous tyramine in patients receiving monoamine-oxidase inhibitors (MAOIs). Dothiepin and trimipramine, however, produced little change in sensitivity to tyramine. It is suggested that a combination of amitriptyline and an MAOI, started together in a modest dose that is then increased, may protect patients against the potential dangers of eating tyramine-containing foods. However, because MAOIs allow a high proportion of ingested tyramine to be absorbed into the systemic circulation, patients treated with MAOIs, even in combination with amitriptyline, should not be encouraged to eat foods containing tyramine.

Adult↗

Schizophrenia and platelet monoamine oxidase: research strategies.

The most widely replicated neurochemical finding in schizophrenia is that of lower levels of monoamine oxidase (MAO) in the platelets of chronic schizophrenics than in normal controls. Yet, the etiological role of MAO in schizophrenia remains to be demonstrated. The incidence of low MAO in other psychiatric disorders, effects of diet, hormones and drugs, and relationships of platelet MAO to brain levels and genetic mechanisms remain unclear. This article examines factors which make any biological indicator suitable for use as a diagnostic test for schizophrenia and inquires into the methodological pitfalls and unexamined assumptions of various research strategies which use this measure.

Age Factors↗

A monoamine oxidase inhibitor reverses the 'separation syndrome' in a new hamster separation model of depression.

A broad spectrum monoamine oxidase inhibitor, tranylcypromine sulfate (Parnate) was tested in a new hamster separation model of depression. In this paradigm, male dwarf hamsters show increases in body weight, decreases in exploratory behaviors, and decreases in social interactions, when separated from female mates. Tranylcypromine (10 mg/kg s.c. daily for 14 days) effectively reduced body weight, increased exploration, and increased social interaction, in the separated males. Subsequent treatment with saline restored the separation-induced changes in body weight, exploratory behaviors, and other social behaviors. The 'separation syndrome' in dwarf hamsters appears to be completely reversed by at least one antidepressant treatment.

Animals↗

Raised endogenous monoamine oxidase inhibitor output in postwithdrawal alcoholics: effects of L-dopa and ethanol.

Urinary output of endogenous monoamine oxidase inhibitor was significantly greater in a group of postwithdrawal alcoholics than in controls. An oral dose of 0.5 g of L-dopa reduced output to control values in the alcoholics, but in the controls themselves output was unaffected. A similar excretion pattern to unextracted samples was observed in ethyl acetate extracts of these urine samples, acidified to pH 1. In a second group of postwithdrawal alcoholics, where the L-dopa effect was confirmed, ethanol administration brought about a small but not significant reduction in inhibitor output.

Adult↗

Type A personalities tend to have low platelet monoamine oxidase activity.

This study investigated whether there are relations between type A behaviours and the activity of monoamine oxidase (MAO) in blood platelets. Forty male nonsmokers completed the Jenkins Activity Survey (JAS) and had a blood sample drawn while at work. The JAS was scored in the traditional manner, yielding scores for ambitiousness (factor A), impatience (factor S), competitiveness (factor H) and job involvement (factor J). High scores on JAS scales were associated with low MAO activity in blood platelets; the correlation between platelet MAO activity and job involvement was significant. The findings agree with previous reports in showing relationships between MAO activity and certain personality traits and support the notion that low activity of MAO may contribute to sympathetic hyperreactivity in type A individuals.

Adult↗

Platelet monoamine oxidase activity in schizophrenia. Relationship to disease, treatment, institutionalization and outcome.

A 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.

Antipsychotic Agents↗

Delineation of anxiety and phobic disorders responsive to monoamine oxidase inhibitors: implications for classification.

Studies of the treatment of panic anxiety and various other states with monoamine oxidase (MAO) inhibitors are critically reviewed. It is concluded that MAOIs have differential effects on several dimensions of pathologic anxiety. The association between depression and anxiety states is also reviewed; it is observed that MAOIs effectively treat severe anxiety and phobic disorders without operating strictly via their antidepressant mechanism. In addition, it is proposed that biologic depression and biologic anxiety should be considered to have some independence from one another. Guidelines for the clinical delineation of anxiety disorders are provided, and the clinical and research implications of the proposal for revision of DSM-III anxiety and phobic disorders section, are outlined in detail. It is suggested that anxiety and phobic disorders be classified into endogenous (disease) and exogenous (nondisease) types.

Alprazolam↗

Central nervous system toxicity after abrupt monoamine oxidase inhibitor switch: a case report.

DESCRIPTION: There have been numerous case reports of adverse reactions involving monoamine oxidase inhibitors (MAOIs), including reactions that developed when one MAOI was substituted for another. Although most reports have usually described a switch from isocarboxazid or phenelzine to tranylcypromine, we report a case of acute central nervous system toxicity possibly associated with a switch from phenelzine to isocarboxazid. SYMPTOMATOLGY: Predominant symptoms included stuporous sensorium, hypertension, tachycardia, tremor, and urinary retention. Onset of symptoms began within 48 hours after the abrupt MAOI switch. CONCLUSIONS: Clinicians must allow a sufficient washout period before adding any agent that has a known potential to interact adversely with MAOIs. In addition, patients who are unusually sensitive to one type of MAOI may also be at increased risk for developing problems with a different MAOI secondary to unforeseen pharmacokinetic or pharmacodynamic effects, even at doses that are usually considered subtherapeutic.

Brain↗

[Multiple forms of thrombocyte monoamine oxidase in patients with manic-depressive psychosis and recurrent schizophrenia].

The concentrations of different forms of monoamine oxidase (MAO) in platelets of the peripheral blood from healthy subjects (n = 13), patients with recurrent schizophrenia (n = 6) and those with manic depressive psychoses (n = 5) were measured. MAO of platelets of the peripheral blood from the control subjects and patients with the considered diseases consisted of three forms: MAO-1, MAO-2, and MAO-3. Analysis of the values of the specific activity of each of the studied forms failed to show any significant difference between the patients and controls. Comparison of the quantitative distribution of different forms of MAO in both groups revealed no difference between the groups with regard to MAO-2 and MAO-3 and a significant (P less than 0.01) decrease in MAO-1 (5.34 +/- 1.5%) in patients with mental diseases as compared to this parameter (19.0 +/- 6.5%) in the control group.

Adsorption↗

Negative symptoms and platelet monoamine oxidase activity in male schizophrenic patients.

A significant positive correlation was found between negative symptoms and platelet monoamine oxidase (MAO) activity in unmedicated male, but not female, schizophrenic patients. This correlation was significant in split halves of the male patients. There was no indication that the correlation was due to either outliers or medication effects. Male schizophrenic patients with high negative symptom scores had significantly higher mean platelet MAO activity than either male normal control subjects or male schizophrenic patients with low negative symptom scores. This finding suggests that the extent of negative symptoms in a population of males could affect whether the schizophrenic subjects will be found to have platelet MAO activity which differs from that of normal control subjects. The implications of the correlation between platelet MAO activity and negative symptoms for the role of brain MAO activity and two of its substrates, dopamine and serotonin, in the etiology of negative symptoms in male schizophrenic patients are discussed.

Adult↗

Low platelet gamma-aminobutyrate aminotransferase and monoamine oxidase activities in chronic alcoholic patients.

The activities of gamma-aminobutyrate aminotransferase (GABA-T) and monoamine oxidase (MAO) were estimated in blood platelets from 25 male chronic alcoholics and from 27 healthy male volunteers without histories of alcohol abuse. Based on clinical criteria, the alcoholics were classified into type 1 or type 2 alcoholism. The activity of GABA-T was found to be lower both in type 1 and type 2 alcoholics than in healthy volunteers. With regard to MAO, the platelet activity was found to be significantly lower only in type 2 alcoholics in concordance with previous reports. No significant correlation was found between the activities of GABA-T and MAO in the blood platelets of healthy volunteers. The inhibitory effect of 400 mM ethanol on the platelet MAO activity increased with decreasing concentrations of the substrate phenylethylamine. The degree of inhibition of ethanol on the platelet MAO activity, however, did not differ significantly between alcoholics and controls.

4-Aminobutyrate Transaminase↗

Endogenous monoamine oxidase A inhibitory activity (tribulin), measured in saliva, is related to cardiovascular reactivity in normal individuals.

Salivary monoamine oxidase A inhibitory activity (MAO-AI), mean arterial blood pressure (MAP) and heart rate (HR) were determined simultaneously in healthy male students (n = 13) at rest, before a mild psychological stressor, twice during the task and 18 minutes after the end of the task. The sample as a whole showed significant differences in MAP and HR across occasions (respectively, p < 0.001 for both). Salivary MAO-AI could distinguish novice and experienced game players (p < 0.02) and was consistently positively correlated with MAP (r = 0.58, p < 0.05 on occasion 2). Pre-task measures of MAO-AI for an increased sample (n = 18) were associated with higher MAP (but not HR) throughout the experiment (p < 0.05). Those subject with falling MAO-AI profiles from task to recovery showed significantly greater simultaneous decline in HR than those with a rising MAO-AI profile (p < 0.05).

Adult↗

Determination of platelet monoamine oxidase activity by high-performance liquid chromatography with electrochemical detection.

A procedure for determining human platelet monoamine oxidase (MAO) with dopamine (DA) as substrate is described. High-performance liquid chromatography (HPLC) with electrochemical detection (ED) was used to separate and detect components of the reaction mixture. The method for platelet preparation was also improved and only 2 ml of blood were required. Following a 10-min incubation of the platelet preparation with DA in 0.1 M Tris buffer (pH 9.0), excess DA substrate was removed by adsorption on a cation-exchange resin. The reaction product, 3,4-dihydroxyphenylacetaldehyde, was adsorbed on acid-washed alumina, eluted with 0.1 M perchloric acid and analyzed by HPLC. Simple, clean chromatograms were obtained with good reproducibility using 3,4-dihydroxybenzylamine as an internal standard. The within-sample, between-samples and between-day relative standard deviations were 0.9, 3.7 and 6.1%, respectively. The apparent Michaelis constant and maximum velocity were 0.10 mM and 0.37 nmol/min.mg protein, respectively. This HPLC-ED method offers a good alternative to methods using radioactivity.

Blood Platelets↗

Monoamine oxidase (MAO), 5-hydroxyindole acetic acid (5 HIAA) and homovanillic acid (HVA) in motor neuron disease.

Thrombocyte monoamine oxidase (MAO) activity and concentrations of 5-hydroxyindole acetic acid (5-HIAA) and homovanillic acid (HVA) in the cerebrospinal fluid (CSF) were studied in patients with motor neuron disease (MND) and healthy controls. The MAO activity in MND (n = 32) did not differ from age and sex-matched controls (n = 27) or from healthy relatives (n = 9) and no difference was found between advanced and mild cases. In an attempt to explain divergent results from other studies, the effect of storage time on analysis of platelet concentration was studied in three healthy subjects and in three patients with MND. No difference was observed between the groups. No differences were found between the MND group (n = 28) and healthy controls (n = 18) with regard to CSF levels of 5-HIAA and HVA, except for an increase of 5-HIAA among males with MND. The results of this study do not confirm earlier studies that have reported extensive changes in the variables analyzed in patients with MND.

Blood Platelets↗