Plasma Amine Oxidase Activity Research Articles

Inhibition of lymphocyte growth by spermidine in medium containing fetal bovine serum.

The effect of spermidine and fetal bovine serum on DNA, RNA, and protein synthesis in phytohemagglutinin-stimulated human lymphocytes was investigated. At 10(-4) M spermidine, DNA, RNA, and protein synthesis ceased and 70% of the original cell population died within 62 hr. Lower spermidine concentrations had no significant effect on DNA and protein synthesis, but caused an early, unexplained increase in the rate of RNA synthesis. Heating at 56 degrees C for 30 min had no effect on the plasma amine oxidase activity in fetal bovine and horse sera but abolished the activity in human plasma. It is concluded that low amounts of aminoaldehydes and acrolein produced by plasma amine oxidase at spermidine concentrations below 10(-4) M do not noticeably alter lymphocyte metabolism. However, the aminoaldehydes and acrolein produced become abruptly cytotoxic at 10(-4) M spermidine.

Platelet monoamine oxidase and plasma amine oxidase in psychiatric patients.

Platelet monoamine oxidase (MAO) and plasma amine oxidase (PAO) activities were determined in 70 normal controls and 76 psychiatric patients. Platelet MAO activity did not differ between the normal controls and patients diagnosed as schizophrenic or primary affective illness, although there was a strong trend for chronic schizophrenics to have lower MAO activity. Schizophrenic patients with Schneiderian-type hallucinatiions had significantly lower MAO activity than normal controls or schizophrenic patients who did not hallucinate. There was no relationship between hallucinations and platelet MAO activity in patients with affective psychoses. Paranoid schizophrenics did not have significantly different MAO activity from nonparanoid schizophrenics. PAO activity was generally lower in all diagnostic groups than in normal controls, but the results were statistically significant only for acute schizophrenics.

Inhibition of beef plasma amine oxidase activity by glycine

Inhibition of beef plasma amine oxidase activity by glycine

Platelet and plasma amine oxidase activity in alcoholic individuals.

Platelet and plasma amine oxidase activity was determined in a group of 99 healthy male (active duty military) alcoholics referred for hospital treatment who had been abstinent from alcohol for 2-10 days, and compared with that of a control military group. Platelet MAO activity was slightly but significantly lower in the alcoholic group. Both groups were significantly lower in MAO activity compared to a group of 42 non-military controls. In the alcoholic group there was no correlation between platelet MAO and severity or chronicity of drinking, nor was there evidence of iron deficiency to account for the lowered MAO activity. When the alcoholic and military control groups were split at the median, the first degree relatives of both the 'low' MAO alcoholics and the 'low' MAO military controls had a higher incidence of alcoholism than did the relatives of both 'high' MAO subgroups. No personal or family history data of alcohol-related problems were available on the non-military control group.

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.

Biogenic amine-related enzymes and personality variations in normals.

Altered activities of biogenic amine-related enzymes have been reported in some studies of patients with affective disorders and chronic schizophrenia. To evaluate whether any relationship between personality variations, including non-diagnosed psychopathology, and these enzymes might occur in non-psychiatric patients, 95 young adult volunteers were studied. Higher MMPI and Zuckerman sensation--seeking scale scores were found in male, but not female, volunteers with lower platelet and plasma amine oxidase activities. Males generally exhibited negative correlations, while females had positive correlations between the psychological test scores and amine oxidase activities. In contrast to the amine oxidase results, no associations were observed between plasma dopamine beta-hydroxylase activities and the personality variables.

Platelet and plasma amine oxidase inhibition and urinary amine excretion changes during phenelzine treatment.

The treatment of depressed patients with the monoamine oxidase (MAO)-inhibiting antidepressant, phenelzine, was found to be accompanied by an 82 per cent reduction in platelet MAO activity and a 91 per cent reduction in plasma amine oxidase activity. Maximum reductions in enzyme activity occurred after 7 to 14 days of treatment; recovery of enzyme activity posttreatment required an average of 14 days for the platelet MAO and greater than 6 weeks for the plasma enzyme. Marked elevations in urinary tryptamine excretion occurred in conjunction with MAO inhibition during phenelzine treatment, but the magnitidue of urinary tryptamine change in individual patients was not closely correlated with the magnitude of enzyme activity reduction. Changes in platelet serotonin content serotonin content and in urinary catecholamine metabolites also occurred in response to phenelzine treatment.

Platelet and plasma amine oxidase activity in 680 normals: Sex and age differences and stability over time

Platelet and plasma amine oxidase activities in 680 normals exhibited unimodal frequency distributions. Females had 20% higher mean platelet amine oxidase activities, but there were no male-female differences in the plasma enzyme. Age was not significantly correlated with either platelet or plasma amine oxidase activities. The activities of the two enzymes were not significantly intercorrelated. Platelet amine oxidase activity measured with benzylamine as the substrate in a rapid assay based upon platelet counts was highly correlated ( r = 0.88) with activity measured in platelet pellets with tryptamine as the substrate. Benzaldehyde and indoleacetaldehyde were identified as the principal products in these assays. Platelet and plasma amine oxidase activities determined three times in the same individuals yielded similar results after approximately 2-week ( r = 0.94, 0.97) and 2-month ( r = 0.86, 0.84) intervals.

Pre- and post-partum plasma amine oxidase differences in the rhesus monkey (Macaca mulatta).

Plasma amine oxidase activity increased from 23.4 nmol/ml/h during pregnancy to 49.5 nmol/ml/h during an extended post partum period in 10 rhesus monkeys. Comparison with non-pregnant control monkeys sampled at similar times indicated that the significant differences were in the extended post partum period.

Effect of copper status on brain neurotransmitter metabolism in the lamb.

Abstract— Ataxic and non‐ataxic lambs reared under field conditions which gave rise to low copper status were treated with copper intravenously. Untreated ataxic animals served as controls. The neurotransmitter amines, dopamine, norepinephrine and serotonin, were determined in the anterior and posterior regions of the brain stem. Dopamine levels in the anterior region, including the corpus striatum, were significantly lower in the untreated animals than in those treated with copper. Norepinephrine levels were also lower but serotonin concentrations were not different. Plasma amine oxidase activity was markedly higher in the copper treated animals but monoamine oxidase activity in brain stem homogenates was not significantly affected. The monoamine oxidase activity in cortical and cerebellar homogenates was significantly lower in the treated animals than in the untreated animals.

Serotonin vascular reactivity and other clinical pharmacological investigations in two intestinal carcinoid patients.

In two patients with carcinoid syndrome, a reduced venoreactivity to serotonin (5-HT) was found by means of the venoconstriction test. Parachlorophenylalanine (PCPA) treatment increased 5-HT venoreactivity. A normal noradrenaline venoreactivity was detected before and during PCPA administration. The altered platelet monoamine oxidase (MAO) activity corrected by PCPA treatment. The abnormal 5-HT turnover may alter the synthesis of MAO and provoke the production of isoenzymes. Low plasma amine oxidase and high plasma histaminase activity were found in 1 of these 2 patients. A low level of plasma prekallikrein in the two patients remained unchanged during PCPA administration.

A simple method to identify plasma amine oxidase activity band on polyacrylamide gel

Specific enzymatic bands in disc gel electrophoresis are generally determined by either of two methods: (i) Gel is sliced and the enzymatic activity is assayed on each slice or (ii) gel is stained histochemically, if the product of the enzymatic reaction and the dye can form an insoluble precipitate, and the activity band is located on the gel by a color band. The former is laborious and often inaccurate in the calculation of electrophoretic mobility. The latter, often nonspecific, is not applicable when the enzymatic product cannot form an insoluble precipitate with the dye. Staining with tetrazolium salt has been widely employed for amine oxidase (1–6). However, this method has limitations: (i) Tetrazolium salt is nonspecific for amine oxidase and may show artifacts (6,7), and (ii) the use of tetrazolium salt is limited only to substrates containing indolamine such as tryptamine or serotonin (8). Other substrates, like benzylamine, the most active substrate for plasma amine oxidase, do not form a color band with tetrazolium salt. This communication reports a simple spectrophotometric method for the identification of the enzymatic activity band for amine oxidase on disc gel electrophoresis. Neither slice and assay nor staining is needed. This method may possibly also be used generally for other enzyme systems which have a specific absorption at ultraviolet or visible range.

Effects of drugs on human blood platelet and plasma amine oxidase activity in vitro and in vivo

A method employing radioactive substrates has permitted sensitive assay of monoamine oxidase (MAO) activity in blood platelets and plasma. Kinetic studies indicate that while platelet and plasma MAO are distinct from that of liver mitochondria, the platelet and liver enzymes are quite similar, particularly in the characteristics of their response to inhibitors. Administration of six different MAO inhibitors including furazolidone to human subjects resulted in marked inhibition of platelet MAO, accompanied by expected changes in urinary tryptamine excretion. Effects of these drugs on plasma MAO were variable; an additional drug, isoniazid, in therapeutic dose was found to inhibit markedly plasma, but not platelet, MAO. Use of platelet MAO assay in the direct assessment of the MAO-inhibitory potency of drugs in man is suggested.