Relation of sex and aging to monoamine oxidase activity of human brain, plasma, and platelets

Correlation of anxiety and related symptoms with cerebrospinal fluid 5-hydroxyindoleacetic acid in depressed women

Cerebrospinal fluid 5-hydroxyindoleacetic acid levels were determined in 31 women with unipolar involutional depression using the probenecid technique. Values were found to be lower in depression as compared to controls, but they did not correlate with the severity of the clinical picture. Anxiety, insomnia and drug response however showed significant correlation with pretreatment 5-HIAA level. Some possible interpretations are discussed.

Reinforcing properties of intravenous procaine in rhesus monkeys

The lever pressing behavior of rhesus monkeys was maintained by a fixed ratio 10 schedule of intravenous cocaine (3 monkeys) or codeine (2 monkeys) injections during 2 hour sessions. Saline or various doses of procaine hydrochloride were substituted for the baseline reinforcer for 6 consecutive sessions. Each substitution was separated by 3 or more days of cocaine or codeine reinforced responding. At one or more doses, procaine substitution resulted in response rates higher than saline control in all 5 animals. High response rates (greater than 30 injections per session) were obtained in 4 of the 5 monkeys. In addition, procaine self-administration was studied in two naive monkeys given 23 hour per day access to procaine following an initial 10 days of saline contingent operant level responding. At a dose of 0.3 mg/kg/injection, both animals initiated responding for procaine reinforcement. Drug intake varied widely from day to day, however each animal took over 1200 injections per day (over 360 mg/kg) at least once during the 30 days of access. With the exception of decreased food intake, there was little evidence for behavioral toxicity from these doses. Following a second 10 days of saline self-administration, both animals were given access to 3.0 mg/kg/injection procaine. A substantially greater intake of procaine was observed which was associated with marked toxicity.

Monoamine oxidase activity in blood platelets from manic and depressed patients

To evaluate the possible abnormality in MAO activity in affective disorders, blood platelet samples were obtained from 80 patients with mania and depression. Blood-platelet MAO activity was measured by a newly developed assay procedures using serotonin as substrate. MAO activities in 121 normal adult subjects were in a range of 2.49-12.05 nM/mg protein/hour, with the mean values of 4.91 +/- 1.72 (+/-S.D.) for men and 6.88 +/- 1.99 for women. (p less than 0.001) MAO activities in the manic and depressed patients were in a range of 0.65-13.40 nM/mg protein/hour, and both manic and depressed patients showed the mean value very familiar to that in the normal subjects. Bipolar depressed patients did not exhibited lower MAO activity in the blood platelets than other clinical subtypes of depressive illness, including unipolar, involutional, neurotic and chronic characterological, and first-episode depression. No significant differences were established between these five subcategories of depression, while significant higher values were evident in female than male patients (p less than 0.001). No correlation was found between the MAO activity and serotonin levels in the blood platelets either in the normal subjects or in the depressed patients.

Monoamine oxidase in chronic schizophrenia: Studies of hormonal and other factors affecting enzyme activity

Reported reductions in the activity of platelet monoamine oxidase (MAO) in chronic schizophrenic patients might be contributed to by alterations in hormones, platelet numbers or other non-specific factors thought to affect enzyme activity. In this study, MAO activity in 27 patients with chronic schizophrenia was measured, using benzylamine as the substrate in an assay based on platelet counts instead of platelet protein, and was found to be markedly lower than mean MAO activity in 375 normal controls. These results were similar to those previously reported with tryptamine as a substrate for the enzyme. Serum testosterone, triiodothyronine, iron and iron-binding capacity were within normal ranges in individuals with reduced MAO activities. Platelet MAO activity remained stable over time in patients and controls.

Monoamine oxidase activity in blood platelets in alcoholism

A newly developed assay for monoamine oxidase (MAO) activity in blood platelets was applied in 50 alcoholic patients. The assay is the direct measurement of serotonin oxidation by MAO employing a double microcolumn technique on Sephadex G-10 and Amberlite CG-50 for separating 5-HIAA formed, which is measured fluorimetrically. Rebound of MAO activity levels after withdrawal of alcohol was observed to be more pronounced in the patients with delirium tremens than those who exhibited no outstanding abstinent symptomatology. MAO activity levels measured in the 1st week of alcohol withdrawal were 3.49 +/- 1.15 (Mean +/- S.D) nmol/mg protein/hour in the alcoholic patients with delirium tremens, a value significantly lower than that in the subjects without (p less than 0.01) and that in the male normal subjects (p less than 0.001). Four weeks after withdrawal of alcohol, the reduced MAO activity levels in the alcoholic population were restored to normal levels. These data demonstrate that physical dependency for alcohol occurred evidently in the alcoholic patients examined. Delirium tremens and other psychotic symptoms in alcoholism may be manifested as impaired serotonin metabolism in the brain, which may be due to MAO inhibition caused by excessive alcohol intake.

EEG, 5-HTP-metabolism and acupuncture

Correlations between EEG-alterations and administration of 5-HT and 5-HTP in man are described. Age-dependence can be observed. Successful acupuncture produces EEG-alterations especially in younger patients as seen after exogene administration of 5-HT respectively 5-HTP i.v. Since biochemical indications for an increased 5-HT turnover during acupuncture of several acupuncture-points are evident further investigations should be carried out to enable reliable correlations.

Time course of nigrostriatal degeneration in parkinson's disease. A detailed study of influential factors in human brain amine analysis

It could be shown that the post mortem analysis of biogenic amines, precursors and metabolites in the human brain are influenced by various parameters. 1. The patient's medical history; long term observations of the course of the disease; age; sex. 2. Terminal illness; duration of terminal illness. 3. Previous treatment with drugs; last drugs. 4. Time interval between last drug treatment and death; time of day and date of last drug consumption. 5. Rapidity of death; time of death; duration of coma. 6. Changes occurring in tissues before death; patients' constitution during terminal illness. 7. Changes in concentration of the biogenic amines, precursors, and metabolites depending on the patient's age. 8. Time between death and necropsy. 9 Dissection of specimen. 10. Period of storage; temperature of storage. 11. Chronbiological rhythm of substances. 12. Methods of assayL 13. Homogeneity of all mentioned parameters in the control group and patient's group. For the first time it could be demonstrated that the time course of nigrostriatal degeneration, independent of the age of the parkinsonian at the beginning of the illness, is linear for the last stage and the denervation progressively increases as the duration of illness progresses.

Platelet monoamine oxidase in schizophrenia and manic-depressive illness

Monoamine oxidase (MAO) is an important enzyme in the catabolism of brain biogenic amines. Platelet MAO has been reported to be moderately reduced in manic-depressive patients and markedly reduced in schizophrenic patients. This enzyme's activity has been shown to be under a large degree of genetic control and has been proposed as a 'genetic marker' in schizophrenia. A transcultural replication of the finding of low platelet MAO in schizophrenia and manic-depressive illness was carried out at the Jerusalem Mental Health Centre. Manic-depressive patients were found to have higher platelet MAO activity than schizophrenic patients, as reported previously, but control individuals were as low as the schizophrenic patients. It is unlikely that platelet MAO activity is a transculturally-valid marker for schizophrenia.

A routine assay procedure for monoamine oxidase and its application to human blood platelets

In the radiometric assay procedure for monoamine oxidase separation of the reaction products by ion-exchange column chromatography was optimized. A device was constructed that allowed the separation of 48 samples at the same time. This device can be applied for a great variety of analytical methods. With a 0.1 mM substrate concentration in the incubation mixture, reaction products could be determined with a reproducibility of 2-5%, where the standard deviation depends on the substrate. Using beta-phenylethylamine as substrate 20 mug of platelet protein was sufficient for monoamine oxidase activity determinations. The dependence of human blood platelet monoamine oxidase on age and sex were studied using the method.

Reduction of blood platelet monoamine oxidase activity in schizophrenic patients on phenothiazines

A newly developed assay for monoamine oxidase (MAO) activity in blood platelets (serotonin used as substrate) was applied for the measurement of the enzyme activity in 76 schizophrenic patients. No significant reduction was found in the blood platelet MAO activity in a group of 33 untreated schizophrenic patients, as compared to that in the normal controls. Male patients revealed to have lower enzyme activity than females in the schizophrenic group, as we described previously in the normal subjects. Treatment with phenothiazines caused significant reduction of blood platelet MAO activity, while platelet serotonin content and platelet count appeared to be not affected by the drug treatment. The authors suggest that blood platelet MAO activity may be related to hormonal factors but not to psychiatric diagnosis of schizophrenia or constitution liable to schizophrenic illnesses.

The potentiation of the anti akinetic effect after L-dopa treatment by an inhibitor of MAO-B, Deprenil

The potentiation of the anti akinetic effect after L-Dopa treatment by an inhibitor of monoamine oxidase (MAO) "B", Deprenil, has been demonstrated in parkinsonian patients with or without previous L-Dopa theapy. Application of the drug has been performed orally, intravenously and intramuscularly. Excellent kinetic effects resulted when combined with Madopar. The combined treatment with L-Dopa was highly effective when applicated i.v. or i.m. Deprenil is an inhibitor of MAO-B and is characterized by less frequent side effects. These are predominantly involuntary movements and confusion, which can be eliminated by lowering the dosage of Deprenil. A daily rhythm of MAO could be demonstrated in several areas of human brains as well as in a control group as in parkinsonian patients with or without L-Dopa therapy. Maximal activity of MAO occurs between noon and 6p.m. The clinical and biochemical data are discussed regarding the off-phenomenons as Deprenil is an excellent drug for preventing these.

A sensitive non-isotopic assay for monoamine oxidase activity in human blood platelets

A sensitive and specific procedure for measuring monoamine oxidase (MAO) activity in human platelets is described. Serotonin is used as substrate and formed 5-hydroxyindoleacetic acid (5-HIAA) is separated by a double microcolumn technique on Sephadex G-10 and Amberlite CG-50 and measured fluorimetrically. MAO activities were 5.11 +/- 1.32 (mean +/- S.D.) nmol/mg protein/hour in male and 7.85 +/- 1.58 in female healthy adults (p less than 0.001). MAO activity measured in 32 depressed patients was in a range of 3.20-10.62 nmol/mg protein/hour, the value not differing from that in the normal subjects. No significant difference was established between three subtypes of depression, in bipolar, unipolar and involutional patients, while significantly higher values were evident in female than in male patients (p less than 0.001).

Depressive disorders: toward a unified hypothesis

Our scientific understanding of psychiatric syndromes, including the phenomena of depression, has been hampered because of: (i) the use of metapsychological concepts that are difficult to test; (ii) methodological and linguistic barriers that prevent communication among psychoanalysts, behaviorists, experimental psychologists, and psychiatrists; and (iii) the reluctance of psychiatrists to accept animal models as possible approximations of certain aspects of human psychopathology. We have attempted to demonstrate that the animal models simulate some of the central features of clinical depression (for example, helplessness and object loss), thereby allowing one to rigorously investigate them from developmental, behavioral, and biochemical perspectives. The object loss model, as a concrete version of a metapsychological-psychoanalytic concept, has enabled primatologists to study the disruption of an attachment bond. The behavioral model accommodates this concept to a broader generalization: loss of reinforcement or loss of control over reinforcement. We have reviewed the evidence that these processes involve the diencephalic centers of reward or reinforcement, thereby permitting integration of the psychoanalytical and behavioral formulations with the biochemical hypotheses. Also, we have presented data strongly suggesting that the breaking of an attachment bond in the primate represents significant loss of reinforcement that induces helplessness and disrupts motivated behavior. Finally, we have argued that the depressive syndrome could be caused by interactions of genetic, chemical, developmental, and interpersonal factors, all of which impinge on the diencephalic centers of reinforcement.

Barbiturate tolerance and psychological functioning in elderly depressed patients

Increases in barbiturate tolerance and in scores on certain cognitive tests were found to have occurred after the treatment of elderly depressives. These changes were related to original severity of illness and to the extent of improvement, as well as to a number of other clinical features including age at first attack. The reported findings lent support to theories linking depressive illness with reduction in cortical arousability.

Growth hormone responses to L-dopa in depressed patients

Plasma human growth hormone responses to oral administration of 500 milligrams of L-dopa were analyzed in three groups of subjects: normals, age 20 to 32; normals, age 48 to 68; and unipolar depressed patients, age 45 to 68. While only 7 percent of the young normals had deficient human growth hormone responses to this stimulus, 36 percent of the older normals and 77 percent of the depressed patients failed to have adequate responses, suggesting an effect of age and a further effect of depressive illness. Because the release of human growth hormone appears to be closely related to brain catecholamine metabolism, the deficient responses in the depressed patients may provide further support to the concept of a neurochemical defect in depressive illness.