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Biomedical subjects

L Oreland

Publications and source records attributed to L Oreland.

At least 181 records · Page 10Linked to original sources
PubMed1984

Pain as a symptom in depressive disorders and its relationship to platelet monoamine oxidase activity.

144 depressed in-patients were rated by means of the Comprehensive Psychopathological Rating Scale (CPRS) and platelet monoamine oxidase (MAO) was determined. 49 per cent of the patients were found to have pain as a symptom, and 21 per cent were found to have more severe pain. The patients with more severe pain were found to have lower platelet MAO activity than the patients without pain or with slight pain. As platelet MAO activity may reflect the turn-over in the serotinergic systems in CNS it is hypothesized that patients with depressive disorders with pain as a symptom may have more pronounced disturbances in the serotinergic systems than patients without pain as a symptom.

Adult↗
PubMed1984

Life events and biological vulnerability: a study of life events and platelet MAO activity in depressed patients.

The present study investigated the possible relationship between platelet monoamine oxidase (MAO) activity and life events. From the general hypothesis that the impact of life events should be seen against the background of an individual's vulnerability, it was assumed that low platelet MAO patients would need fewer life events to develop a psychopathological condition and that they would experience more negatively those events that occurred. Patients (n = 127) of both sexes suffering from various kinds of depressive disorders participated in the study. There were 39 unipolar patients, 11 bipolar patients, 43 patients suffering from neurotic-reactive disorder, and 34 patients suffering from an unspecified depressive disorder. No statistically significant differences in MAO activity were found in this series among the diagnostic subgroups. Younger patients predominated among those with the lowest MAO values. As expected, low MAO patients reported a lower number of life events than patients in the highest MAO quartile, and had experienced those events more negatively.

Adjustment Disorders↗
PubMed1984

Personality traits related to monoamine oxidase activity in platelets.

Platelet monoamine oxidase (MAO) activity and intellectual level were examined in a large series of 1,129 18-year-old boys, selected from the general population. Personality traits were determined by means of selected subscales from several personality inventories such as the Zuckerman Sensation Seeking Scale, the Eysenck Personality Inventory, and the Karolinska Hospital Personality Inventory. Information was also gathered concerning alcohol consumption habits, signs of alcohol dependence, and use and abuse of tobacco, cannabis, glue, opiates, and amphetamine. Low MAO subjects were found to be more sensation seeking and to have higher scores on impulsivity and monotony avoidance. They also had higher use of tobacco and alcohol, showed more signs of possible alcohol dependence, and showed more drug abuse. When low MAO subjects were subdivided according to intellectual level, low MAO subjects with high intellectual level were found to have higher psychological functioning as judged by a psychologist after a clinical interview. Low MAO subjects with low intellectual level were found to have more use and abuse of alcohol and drugs, i.e., less accepted forms of sensation seeking, and they had a significantly lower level of psychological functioning. This subgroup seems to be the real "high risk" group that according to the high risk paradigm could be expected to show more alcohol abuse and higher tendencies to suicidal behavior.

Adolescent↗
PubMed1984

Effect of age on human brain serotonin (S-1) binding sites.

The effect of age on the binding of [3H]5-hydroxytryptamine [( 3H]5-HT, serotonin) to postmortem human frontal cortex, hippocampus, and putamen from individuals between the ages of 19 and 100 years was studied. One high-affinity binding site was observed in adult brains, with a mean KD of 3.7 nM and 3.2 nM for frontal cortex and hippocampus, respectively, and 9.2 nM for putamen. Decreased binding capacities (Bmax) with age were detected in frontal cortex and hippocampus. In putamen a decrease in affinity was noted. Postmortem storage did not significantly contribute to the age-related changes. No significant sex differences were detected. [3H]5-HT binding was also studied in brains from human neonates. The specific binding was 1.5-3 times lower than in adult frontal cortex and putamen, and Scatchard analysis suggested more than one binding site. In infant hippocampus a single binding site was observed and except for a premature individual, the binding capacity approximated adult values.

Accidents↗
PubMed1984

Personality traits and monoamine oxidase activity in platelets in depressed patients.

Personality characteristics and platelet monoamine oxidase (MAO) activity have been assessed in 143 depressed patients of both sexes (60 males and 83 females) in the age range 21-65 years (mean age 44.8 +/- 12.8, SD), the personality inventory being completed by the patients when recovered, or at least markedly improved from the depressive disorder. In line with previous studies, a significant negative correlation between MAO activity and the variables, impulsivity and monotony avoidance, was found in the whole series. A significant negative correlation between MAO activities and the traits reflecting verbal aggression and irritability was also found. A separate analysis showed that those correlations hold true for female but not for male patients.

Adult↗
PubMed1984

Effect of perchlorate treatment on mitochondrial MAO-A and -B activities.

Rat liver mitochondrial monoamine oxidase-A (MAO-A) and -B (MAO-B) were solubilized and isolated by procedures that included two cycles of treatment with a non-ionic detergent, Triton X-100, and then treatment with sodium perchlorate. After the treatment cycles with Triton X-100 about 23 and 36% of the original mitochondrial MAO-A and MAO-B activity, respectively, towards 0.1 mM serotonin and benzylamine remained in the residue. Of those activities, virtually no (2%) MAO-A activity, but appreciable (28%) MAO-B activity survived in the soluble state after the subsequent perchlorate treatment. The Km value and molecular turnover number of the soluble MAO-B, for benzylamine, were similar to those of the original activity in mitochondria, suggesting that this form of MAO has not undergone any qualitative change. After selective labelling of either form of MAO in mitochondria with 3H-pargyline and application of the isolation procedures, similar amounts of labelled MAO-A and -B were found in a soluble state, indicating that both forms of the enzyme were solubilized by the perchlorate treatment but that MAO-A was present in an inactivated state.

Animals↗
PubMed1983

The activity of monoamine oxidase -A and -B in brains from chronic alcoholics.

The activity of monoamine oxidase--A was found to be lower in homogenates of hypothalamus and caudate nucleus, but not in cortex of the gyrus cinguli and hippocampus, from chronic alcoholics with respect to homogenates from autopsy cases without histories of alcohol abuse. The activity of monoamine oxidase--B was also lower in the alcoholics, but this could be due to the selective effect of age upon this enzyme form, since the alcoholics were younger than controls. No difference was found for either monoamine oxidase -A or -B activities in brain homogenates from an alcohol preferring (AA) strain of rats, with respect to those from a water preferring (ANA) strain.

Aged↗
PubMed1983

Serotonin binding in mouse brains. Some methodological aspects.

The binding of (3H)5-hydroxytryptamine ([3H]5-HT, serotonin) to crude homogenates of brains from three different strains of mice has been studied. The strains, C57/BL, DBA and BALB did not show significant differences in the binding characteristics, with Kd values around 6-7 nM and Bmax 270-310 fmoles/mg protein. Various methodological aspects were investigated and found to be important for the binding assay. The presence of ascorbic acid (5.7 mM) thus caused a significant increase in Bmax by 30% without any change in the Kd values. This increase seemed to be due to a decrease in the non-specific binding rather than to an increase in the total binding of serotonin. The presence of a specific MAO-A inhibitor, clorgyline (10 microM), during the assay, resulted in a significant reduction of Bmax by 20% without any change in the affinity for serotonin, when tissue which had been frozen was used. Less than 2% of added serotonin was metabolized during the binding procedure in the absence of clorgyline. Thus, the decrease in binding capacity caused by clorgyline, may be due to a non-competitive blocking effect of the serotonin binding structure. These results indicate that the use of MAO inhibitors in (3H)5-HT binding assays on frozen tissue, rather than being necessary, might negatively affect the result. Neither storage of the brains at -70 degrees nor postmortem storage of the animals for 60 hours at 4 degrees resulted in obvious changes in the (3H)5-HT binding characteristics.

Animals↗
PubMed1983

Biochemical changes in dementia disorders of Alzheimer type (AD/SDAT).

In postmortem investigations of patients with dementia of Alzheimer type (AD/SDAT) (n = 14) the brain weight was significantly reduced when compared to controls (n = 16). In four AD/SDAT-brain parts investigated the concentrations of 5-hydroxy-tryptamine and noradrenaline were significantly reduced while 3-methoxy-4-hydroxyphenylglycol was significantly increased. In the caudate nucleus of the AD/SDAT-brains the concentrations of dopamine and homovanillic acid were significantly reduced. The activity of monoamine oxidase B was increased suggesting a proliferation of extra neuronal tissue in the AD/SDAT-brains. The activity of choline acetyl transferase was reduced in the four brain parts investigated, showing a general reduction in the acetylcholine system in the AD/SDAT-brains. The ganglioside concentration was significantly reduced suggesting a reduced density of nerve endings in the demented brains. The AD/SDAT-group was according to rating scales severely demented. Patients with an early onset of the dementia disease were more severely intellectually reduced and had more pronounced biochemical disturbances than those with a late onset of the dementia.

Aged↗
PubMed1983

Superoxide dismutase activity in brains from chronic alcoholics.

CuZn superoxide dismutase (SOD) and Mn SOD activities were analyzed in hypothalamus, nucleus caudatus, hippocampus and cortex gyrus cinguli from 12 chronic alcoholics and from 16 controls. The CuZn SOD activities were slightly lower and the Mn SOD activities were slightly higher in the brain pieces from chronic alcoholics compared to the controls. The slight differences found can hardly be assigned etiological importance in the degenerative processes in brain tissue connected with chronic alcoholism.

Adult↗
PubMed1983

The effect of deprenyl (selegiline) on intra- and extraneuronal dopamine oxidation.

It was found that in the rat striatum DA was oxidized extrasynaptosomally to 11% by MAO-A and to 3% by MAO-B. The corresponding intrasynaptosomal oxidations were 84% and 2%, respectively. Those figures were virtually unchanged even if the rat brain MAO-B was selectively inhibited to 87% by deprenyl. In the human brain extrasynaptosomal oxidation was 16% and 66%, respectively, by MAO-A and -B. Intrasynaptosomally the corresponding figures were 12% and 6%, respectively. Selective inhibition of human caudate MAO-B was calculated to give a total reduction of DA oxidation of 63%. The differences between man and rat are due to the proportionately greater oxidation of DA by MAO-B in man, which is a consequence of a higher ratio of concentration of MAO-A/-B in the rat.

Animals↗
PubMed1983

Dose regimen of deprenyl (selegiline) and platelet MAO activities.

The effect of various doses of deprenyl on thrombocyte MAO activity in parkinsonian patients has been studied. It is suggested that individual differences in the degree of inhibition are due to differences in the metabolic rate of deprenyl. The recovery of thrombocyte MAO activity was linear at a rate of approximately 10% per day. The linearity of the recovery suggests that the disappearance of the population of thrombocytes is selected with respect to age.

Blood Platelets↗
PubMed1983

Platelet MAO activity in patients with chronic pain syndrome. Relationship to personality traits, endorphins in CSF and plasma cortisol.

Platelet MAO activity was investigated in 32 healthy volunteers and 22 patients with chronic pain syndrome. The MAO activity did not differ between the healthy volunteers and the pain patients. There was a tendency for patients with low platelet MAO activity to have somewhat longer pain duration and somewhat higher pain levels but the difference was not statistically significant. Patients with low platelet MAO activity were found to have higher values on the Zuckerman sensation seeking scale, a disturbed diurnal pattern of plasma cortisol and a tendency towards lower concentrations of endorphins in CSF. It is postulated that platelet MAO activity reflects the activity of the serotoninergic part of the serotonin--ACTH--cortisol system.

Adult↗
PubMed1982

Some properties of monoamine oxidase and a semicarbazide sensitive amine oxidase capable of the deamination of 5-hydroxytryptamine from porcine dental pulp.

The deamination of 5-hydroxytryptamine, tryptamine and benzylamine by porcine dental pulp membrane preparations is brought about not only by monoamine oxidase, but also by a clorgyline (and deprenyl) resistant), semicarbazide sensitive enzyme. The semicarbazide sensitive enzyme was also inhibited by aminoguanidine, hydroxylamine and phenylhydrazine, but was not affected to any significant extent by incubation at 50 degrees for up to 100 min. There was, on the other hand, considerable inhibition of monoamine oxidase activity after incubation at this temperature. The semicarbazide sensitive enzyme neither metabolised, nor was inhibited by putrescine or cadaverine. Mixed substrate experiments indicated that 5-hydroxytryptamine and tryptamine interacted at the same catalytic centre on the semicarbazide sensitive enzyme.

Amine Oxidase (Copper-Containing)↗
PubMed1982

Time-dependent inhibition of monoamine oxidase by beta-phenethylamine.

Several reports have suggested that monoamine oxidase activity towards beta-phenethylamine is inhibited by high concentrations of that substrate. This inhibition is not found if initial velocities are measured, but there is a slower time-dependent inhibition at higher beta-phenethylamine concentrations. Such time-dependent inhibition is not found with tyramine as substrate or upon incubation of the enzyme with the reversible inhibitor amphetamine. The inhibition is not due to the accumulation of phenacetaldehyde, phenylethanol or phenacetic acid, or to a reaction of any of these three products either with each other or with beta-phenethylamine. Although the inhibition is time-dependent, the inactivated enzyme slowly regains activity upon removal of the beta-phenethylamine. A model is proposed to explain the observed inhibition.

Animals↗