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Expression of A and B types of monoamine oxidase in neuroblastoma hybrid cells. Neurochem Int 2012; 3:137-42. [PMID: 20487817 DOI: 10.1016/0197-0186(81)90032-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/1980] [Accepted: 12/25/1980] [Indexed: 11/20/2022]
Abstract
Monoamine oxidase (MAO) activity towards kynuramine as substrate was measured in 6 hybrid cells derived by fusion of neuroblastoma and glioma, liver or brain cells, and was compared with that of parental or non-parental clones. Activities varied from the lowest level of less than 0.15 pmol/min/mg protein in a neuroblastoma clone NB2A to the highest level of 127 pmol/min/mg protein in NCB20 mouse neuroblastoma x Chinese hamster embryo brain hybrid cells. The relative proportions of A and B types of MAO activities were determined in homogenates of each cell line by inhibition curves with clorgyline and deprenyl. Although the A type activity was found in all cell lines measured, MAO A was predominant in 9 clones, except for NCB20 hybrid cells, N4G-B-a neuroblastoma x glioma hybrid cells, and G8-1 myoblast. The ratio of type A/type B activity in NCB20, N4G-B-a and G8-1 cells was 20/80, 75/25 and 95/5, respectively. The results suggest that NCB20 cells are highly enriched in MAO type B, and that the NCB20 cell is an excellent model for studying the type B activity found in the brain in vivo.
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Nagatsu T, Sawada M. Molecular mechanism of the relation of monoamine oxidase B and its inhibitors to Parkinson's disease: possible implications of glial cells. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 2006:53-65. [PMID: 17447416 DOI: 10.1007/978-3-211-33328-0_7] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Monoamine oxidases A and B (MAO A and MAO B) are the major enzymes that catalyze the oxidative deamination of monoamine neurotaransmitters such as dopamine (DA), noradrenaline, and serotonin in the central and peripheral nervous systems. MAO B is mainly localized in glial cells. MAO B also oxidizes the xenobiotic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to a parkinsonism-producing neurotoxin, 1-methyl-4-phenyl-pyridinium (MPP+). MAO B may be closely related to the pathogenesis of Parkinson's disease (PD), in which neuromelanin-containing DA neurons in the substantia nigra projecting to the striatum in the brain selectively degenerate. MAO B degrades the neurotransmitter DA that is deficient in the nigro-striatal region in PD, and forms H2O2 and toxic aldehyde metabolites of DA. H2O2 produces highly toxic reactive oxygen species (ROS) by Fenton reaction that is catalyzed by iron and neuromelanin. MAO B inhibitors such as L-(-)-deprenyl (selegiline) and rasagiline are effective for the treatment of PD. Concerning the mechanism of the clinical efficacy of MAO B inhibitors in PD, the inhibition of DA degradation (a symptomatic effect) and also the prevention of the formation of neurotoxic DA metabolites, i.e., ROS and dopamine derived aldehydes have been speculated. As another mechanism of clinical efficacy, MAO B inhibitors such as selegiline are speculated to have neuroprotective effects to prevent progress of PD. The possible mechanism of neuroprotection of MAO B inhibitors may be related not only to MAO B inhibition but also to induction and activation of multiple factors for anti-oxidative stress and anti-apoptosis: i.e., catalase, superoxide dismutase 1 and 2, thioredoxin, Bcl-2, the cellular poly(ADP-ribosyl)ation, and binding to glyceraldehydes-3-phosphate dehydrogenase (GAPDH). Furthermore, it should be noted that selegiline increases production of neurotrophins such as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and glial cell line-derived neurotrphic factor (GDNF), possibly from glial cells, to protect neurons from inflammatory process.
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Affiliation(s)
- T Nagatsu
- Department of Pharmacology, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan.
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Carrasco G, Cruz MA, Gallardo V, Miguel P, Dominguez A, González C. Transport and metabolism of serotonin in the human placenta from normal and severely pre-eclamptic pregnancies. Gynecol Obstet Invest 2000; 49:150-5. [PMID: 10729753 DOI: 10.1159/000010237] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have attempted to elucidate the possible participation of serotonin as an etiological factor in pre-eclampsia. The transport of serotonin into vesicles from the maternal-facing brush border membrane was measured, as well as the metabolism induced by monoamine oxidase (MAO) in placental homogenate obtained from normal-term and severely pre-eclamptic placentas. Kinetic analysis of serotonin uptake by the placental brush border membrane of the syncytiotrophoblast between normally pregnant and severely pre-eclamptic subjects showed no significant difference (similar Vmax and Km values). However, the metabolism of serotonin was significantly higher in placental homogenate from normal pregnancies than in placentas from severely pre-eclamptic pregnancies. These findings suggest that the higher plasma-free serotonin levels observed in severe pre-eclampsia are mainly due to a reduction in MAO-A activity and not limited by the rate of serotonin uptake into the cells.
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Affiliation(s)
- G Carrasco
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
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Obata T, Egashira T, Yamanaka Y. Isoelectric focusing of isoenzymes of monkey platelet monoamine oxidase. Biochem Pharmacol 1990; 40:1689-93. [PMID: 2242005 DOI: 10.1016/0006-2952(90)90343-j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Monkey platelet monoamine oxidase (MAO) was preferentially found as the B-form of the enzyme as observed from differences in substrate specificities, as well as liver MAO. The isoelectric points and molecular weights of platelet MAO subunits were compared with those of monkey liver using sodium dodecyl sulfate-disc polyacrylamide gel electrophoresis and isoelectric focusing-disc gel electrophoresis. The pI value of monkey liver was a single peak at 6.5, but the pI values of monkey platelets were triple peaks at 5.5, 6.5 and 7.0. The molecular weight of MAO subunits in monkey platelets was similar to that of liver, and was found to be about 60,000. These results indicate that MAO-B of monkey platelets differs from MAO-B of the liver, and that it has different electrophoretic properties.
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Affiliation(s)
- T Obata
- Department of Pharmacology, Medical College of Oita, Japan
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Hertz L, Peng L, Hertz E, Juurlink BH, Yu PH. Development of monoamine oxidase activity and monoamine effects on glutamate release in cerebellar neurons and astrocytes. Neurochem Res 1989; 14:1039-46. [PMID: 2575232 DOI: 10.1007/bf00965940] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Activities of monoamine oxidase (MAO) A and B were measured during the first month of postnatal development in mouse cerebellum and in primary cultures of either cerebellar granule cells or cerebellar astrocytes, derived from 7-day-old cerebella. In addition, effects of the two monoamines, serotonin (a MAO A substrate) and phenylethylamine (a MAO B substrate) on the release of glutamate under resting conditions and in a transmitter related fashion (i.e., potassium-induced, calcium-dependent glutamate release) were studied during the same period. Both MAO A and MAO B activities increased during in vivo development (beginning around postnatal day 14) and in cultured astrocytes (during a comparable time period and to a similar extent), but remained constant at a low level in granule cells. In 4-day-old cerebellar granule cell cultures there was no potassium-induced glutamate release but serotonin as well as phenylethylamine reduced the release in both the presence and absence of excess potassium. In 8- and 12-day-old granule cell cultures and in 8- and 18-day old astrocyte cultures there was a pronounced glutamate release during superfusion with 50 mM K+. In both neurons and astrocytes this response was inhibited by 1 nM of either serotonin or phenylethylamine. In the astrocytes the inhibition was followed by an increased release of glutamate in both the presence and absence of the high potassium concentration, whereas the 8-day-old neurons showed only a slight increase in glutamate release after the withdrawal of the monoamine and only in the absence of excess potassium. The response was almost identical in 8- and 18-day-old astrocytes in spite of the marked difference in MAO activities.
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Affiliation(s)
- L Hertz
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
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Abstract
The human platelet in addition to having serotonin (5-HT) receptors, uptake carriers (receptor) and transmitter storage vesicles, primarily possesses mitochondrial monoamine oxidase (MAO) type B. Similar to the major form of MAO in the human brain, this enzyme actively oxidizes A-B and B substrates (tyramine, dopamine, phenylethylamine) as well as the novel secondary amine anticonvulsant, milacemide and dopaminergic neurotoxin, MPTP. 5-HT oxidation is hardly affected by the platelet enzyme and MAO inhibitors have no net effect on its accumulation. MAO-B is selectively inhibited by 1-deprenyl and thus the platelet enzyme may be useful to monitor the anti-Parkinson activity of such drugs, as related to their ability to inhibit brain MAO-B. The oxidation of the anticonvulsant, milacemide, to glycine in vitro and in vivo by MAO-B, may herald new prospects for the development of inert prodrugs capable of being metabolized to neuroactive substances by MAO-B. The plasma levels of their metabolites may be an index of MAO-B activity found in the platelet and brain.
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Affiliation(s)
- M B Youdim
- Rappaport Family Research Institute, Technion, Haifa, Israel
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Naoi M, Suzuki H, Takahashi T, Shibahara K, Nagatsu T. Ganglioside GM1 causes expression of type B monoamine oxidase in a rat clonal pheochromocytoma cell line, PC12h. J Neurochem 1987; 49:1602-5. [PMID: 3117976 DOI: 10.1111/j.1471-4159.1987.tb01033.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The effects of ganglioside supplementation of culture medium on monoamine oxidase (MAO) type A and B activities in a rat clonal pheochromocytoma cell line, PC12h, were examined. The MAO activity in PC12h cells proved to be mainly due to type A MAO, and type B MAO activity was negligible. After supplementation of the culture medium with ganglioside GM1, the PC12 cells were found to express type B MAO activity after 4 days of culture, and the amount of type B activity increased with the number of days of culture. After 3 weeks of culture in the presence of GM1, type B activity was about 10% of the total, whereas in control cells type B MAO activity was only about 0.6% of the total. By kinetic analyses of type A and B MAO in PC12h cells after 3 weeks of culture, the increase of type B MAO activity was found to be due to the increase in amount of type B MAO; the Km values were almost the same and only the Vmax values were increased in the cells supplemented with GM1. Among gangliosides tested GM1 was the most effective in causing expression of type B MAO activity, whereas nerve growth factor was not effective. These results suggest that GM1 and other gangliosides may be involved in the expression of type B MAO in nerve cells and in the regulation of levels of the biogenic amines in the brain.
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Affiliation(s)
- M Naoi
- Department of Biochemistry, Nagoya University School of Medicine, Japan
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Abstract
Monoamine oxidase (MAO) was characterized in tissue homogenates from rat pancreatic islets, rat neurohypophysis and adenohypophysis, and rat and bovine adrenal medulla and adrenal cortex. Phenylethylamine was preferentially deaminated by rat pancreatic islet and bovine adrenal medulla MAO and with slight preference by rat neurohypophysis MAO, whereas 5-hydroxytryptamine was preferentially deaminated by MAO from all other endocrine tissues. Tyramine was a good substrate for all tissues. Clorgyline, a selective inhibitor of MAO-A, preferentially inhibited deamination of 5-hydroxytryptamine by all tissue homogenates, whereas deprenyl, a selective inhibitor of MAO-B, preferentially inhibited deamination of phenylethylamine. Km values for 5-hydroxytryptamine and tyramine were higher by one to two decimal powers than for phenylethylamine in homogenates from all endocrine tissues. Km values were significantly lower for 5-hydroxytryptamine and significantly higher for phenylethylamine in rat and bovine adrenal cortex than in adrenal medulla. According to these results, the contributions of MAO-B to total enzyme activity were 70% for rat pancreatic islets, 45% for rat neurohypophysis, 15% for rat adenohypophysis, 20% for rat adrenal medulla, 10% for rat adrenal cortex, 60% for bovine adrenal medulla, and 20% for bovine adrenal cortex. PC 12 cells also contained predominantly MAO-A (90%); however, an increased Km for phenylethylamine and a sensitivity of deamination of this MAO-B substrate to inhibition by clorgyline are indicators of abnormal behavior of MAO in this clonal rat pheochromocytoma cell line.
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Obata T, Egashira T, Yamanaka Y. Evidence for existence of A and B form monoamine oxidase in mitochondria from dog platelets. JAPANESE JOURNAL OF PHARMACOLOGY 1987; 44:105-11. [PMID: 3116304 DOI: 10.1254/jjp.44.105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
It is known that platelet MAO appears to behave more like the B-form enzyme than the A-form enzyme based on inhibitor sensitivity and substrate specificity. However, dog platelets showed a different substrate specificity such as high activity with 5-HT and beta-PEA as substrates. Moreover, dog platelet MAO was sensitive to the drugs clorgyline and harmaline with 5-HT as the substrate, while it was sensitive to the drug deprenyl with beta-PEA as the substrate. These results also indicate the existence of two forms of MAO in dog platelets unlike in other platelets such as those from humans. A-form MAO from dog platelets was more stable against heat treatment at 55 degrees C than A-form MAO from dog liver and brain. On the other hand, there was no difference in the heat resistance of the three enzymes with beta-PEA as the substrate. After digestion with trypsin at 37 degrees C for 30 min, it was found that MAO from dog platelets, brain and liver were mostly inhibited with 5-HT as the substrate. In contrast, MAO in brain and liver were inhibited about 10%, but platelet MAO was inhibited about 50% with beta-PEA as the substrate. From these results, it is considered that dog platelet MAO exists as the two forms of the enzyme and has different enzymic properties in comparison with those of MAO from dog liver and brain mitochondria.
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Affiliation(s)
- T Obata
- Department of Pharmacology, Medical College of Oita, Japan
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Ino M, Cole GM, Timiras PS. Tyrosine hydroxylase and monoamine oxidase-A activity increases in differentiating human neuroblastoma after elimination of dividing cells. ACTA ACUST UNITED AC 1986. [DOI: 10.1016/0165-3806(86)90140-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Kato T, Dong B, Ishii K, Kinemuchi H. Brain dialysis: in vivo metabolism of dopamine and serotonin by monoamine oxidase A but not B in the striatum of unrestrained rats. J Neurochem 1986; 46:1277-82. [PMID: 2419508 DOI: 10.1111/j.1471-4159.1986.tb00650.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A dialysis cannula was implanted into rat striatum while the animals were anesthetized, and the area was perfused with Ringer solution while the animals were unanesthetized after at least 3 days following surgery. Concentrations of the metabolites of 3,4-dihydroxyphenylethylamine (DA) and 5-hydroxytryptamine (5-HT) in the perfusate were determined by HPLC with electrochemical detection. Levels of the DA metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the perfusate significantly decreased after pargyline administration (50 mg/kg i.p.), which may inhibit not only monoamine oxidase (MAO)-B but also MAO-A in these high doses. The level of the 5-HT metabolite 5-hydroxyindoleacetic acid (5-HIAA) also decreased after pargyline treatment, although change in the relative level of 5-HIAA was less than that of DOPAC or HVA. To clarify the mechanisms for the metabolism of monoamines in rat striatum, highly specific MAO-A and -B inhibitors were used in the following experiments. Treatment with l-deprenyl (10 mg/kg), a specific inhibitor for MAO-B, did not cause any statistically significant change in DOPAC, HVA, and 5-HIAA levels. No significant change was found in rat striatal homogenates at 2 h after the same treatment with l-deprenyl. In contrast, low-dose treatment (1 mg/kg) with clorgyline, a specific inhibitor for MAO-A, caused a significant decrease in levels of these three metabolites in both the perfusates and tissue homogenates. In addition to the above three metabolites, the level of 3-methoxytyramine, which is an indicator of the amount of DA released, greatly increased after treatment with a low dose (1 mg/kg) of clorgyline.(ABSTRACT TRUNCATED AT 250 WORDS)
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Nakano T, Saito S, Higashida H, Kojima K, Nagatsu T. Assignment of A and B types of monoamine oxidase in NCB20 hybrid cells to those of the parental cells by peptide mapping. J Neurochem 1986; 46:686-94. [PMID: 3081682 DOI: 10.1111/j.1471-4159.1986.tb13026.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The structures of [3H]pargyline-labeled, flavin-containing polypeptides of monoamine oxidase (MAO) from hybrid NCB20 cells, and their parental cells, A/J mouse brain cells and Chinese hamster brain cells, were analyzed and compared by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and limited proteolysis and one-dimensional peptide mapping in SDS gels. After preincubation of mitochondrial preparations with deprenyl or clorgyline, the flavin-containing polypeptide of type A or type B MAO was selectively labeled with [3H]pargyline. SDS-PAGE of [3H]pargyline-labeled mitochondrial samples revealed that the polypeptide with apparent Mr of 62,000 was associated with type A activity in the three types of cells, and that the polypeptide with apparent Mr of 61,000 or 58,000 was associated with type B activity in Chinese hamster brain cells and NCB20 cells or A/J mouse brain cells, respectively. Chymotrypsin digestion of the [3H]pargyline-labeled polypeptides and the peptide mapping in SDS gels from A/J mouse and Chinese hamster brain cells produced identical map patterns between the two type A MAOs, almost the same map patterns (with the exception of one additional peptide fragment) between the two type B MAOs, and different map patterns between type A and type B MAOs. The results of identical treatments of the [3H]pargyline-labeled polypeptides of MAOs in NCB20 cells showed that type A and type B MAO in NCB20 cells were similar to type A MAO of A/J mouse and Chinese hamster brain cells and to type B MAO of Chinese hamster brain cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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Campbell IC, Durcan MJ, Cohen RM, Pickar D, Chugani D, Murphy DL. Chronic clorgyline and pargyline increase apomorphine-induced stereotypy in the rat. Pharmacol Biochem Behav 1985; 23:921-5. [PMID: 4080777 DOI: 10.1016/0091-3057(85)90093-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The effects of monoamine oxidase inhibiting antidepressant drugs on behavioral and biochemical measures of dopamine receptor status were measured in the rat. Male Wistar rats received clorgyline (1 mg/kg/day for 21-28 days), pargyline (1 mg/kg/day for 21-28 days) or a combination of these regimens. They were then either tested for stereotypy induced by 1 mg/kg SC injection of apomorphine or were sacrificed and their striata used to measure specific [3H]spiroperidol binding. All three chronic treatment regimens produced statistically significant increases in apomorphine induced stereotypy: there was, however, no significant difference between the three drug regimens. None of the antidepressant drug treatments significantly affected [3H]spiroperidol binding in the corpus striatum. This study demonstrates that behavioral and biochemical measures of dopamine function may not always be closely correlated. It is proposed that the behavioral changes may be related to alterations in other monoaminergic systems, which are known to have fibres running into the nigrostriatal pathway.
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Francis A, Pearce LB, Roth JA. Cellular localization of MAO A and B in brain: evidence from kainic acid lesions in striatum. Brain Res 1985; 334:59-64. [PMID: 2859911 DOI: 10.1016/0006-8993(85)90567-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The cellular localization of the two forms of monoamine oxidase (MAO A and MAO B) was studied by measuring their activities in rat striatum following unilateral stereotaxic injection of kainic acid to produce selective degeneration of striatal neurons and subsequent proliferation of astrocytes. The results demonstrated a persistent loss of 15-20% in MAO A activity, whereas MAO B activity decreased initially by 25% and then increased to more than twice the control value by 54 days after lesions. The changes in activity were compared to parallel estimates of the postsynaptic neuronal enzyme markers glutamic acid decarboxylase (GAD) and neuron-specific enolase (NSE), astroglial enzyme markers glutamine synthetase (GS) and non-neuronal enolase (NNE), and the presynaptic enzyme marker DOPA decarboxylase (DDC). The results suggest that a small amount of striatal MAO A is present in kainic acid-sensitive postsynaptic striatal neurons and that MAO B is probably localized in both neurons and astrocytes.
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Nakano T, Nagatsu T, Higashida H. Expression of A and B types of monoamine oxidase in differentiated neuroblastoma hybrid cells. J Neurochem 1985; 44:755-8. [PMID: 2983018 DOI: 10.1111/j.1471-4159.1985.tb12879.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The total activities of monoamine oxidase (MAO) and the ratio of type B/type A activities were determined in mouse neuroblastoma N1E-115 cells, and in NX31T and NG108-15 hybrid cells derived from mouse neuroblastoma X rat sympathetic ganglion hybrid or mouse neuroblastoma X rat glioma hybrid cells. N1E-115 and NX31T cells possessed type A activities exclusively, although NG108-15 cells showed both type A (65-90%) and type B (10-35%) MAO activities. The activity of type A MAO in NX31T and N1E-115 cells was relatively constant during culturing periods in the presence or absence of dibutyryl cyclic AMP (Bt2cAMP), whereas total MAO activity and the ratio of type B MAO/type A MAO in NG108-15 cells increased as a function of culture periods. Prostaglandin E1 (PGE1) and theophylline, the best known combination to increase intracellular cyclic AMP content of NG108-15 cells, caused similar increases of MAO and of the type B/type A ratio in NG108-15 cells. The results suggest that MAO activity and expression of MAO B activity are regulated in NG108-15 cells in a cyclic AMP-dependent manner.
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Pollard HB, Ornberg R, Levine M, Kelner K, Morita K, Levine R, Forsberg E, Brocklehurst KW, Duong L, Lelkes PI. Hormone secretion by exocytosis with emphasis on information from the chromaffin cell system. VITAMINS AND HORMONES 1985; 42:109-96. [PMID: 3913120 DOI: 10.1016/s0083-6729(08)60062-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Milligan G, Strange PG. Use of [3H]triphenylmethylphosphonium cation for estimating membrane potential in neuroblastoma cells. J Neurochem 1984; 43:1515-21. [PMID: 6491666 DOI: 10.1111/j.1471-4159.1984.tb06071.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The lipophilic permeant cation [3H]triphenylmethylphosphonium (TPMP) was used to estimate membrane potential in neuroblastoma N1E 115 cells under carefully controlled conditions. The cation distributes into the cells only in the presence of a lipophilic anion, and tetraphenylboron and picrate have been used for this purpose. The potassium salt of tetraphenylboron is poorly soluble, so that studies in high [K+] media are difficult with this anion whereas picrate, at the concentrations required, hyperpolarises the cells. The effect of muscarinic receptor activation was investigated by treating cells with carbachol but no effect was seen either on [3H] TPMP distribution or electrophysiological parameters. The use of [3H]TPMP for qualitative and quantitative evaluation of membrane potential in these cells is discussed.
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McKenna DJ, Towers GH. Biochemistry and pharmacology of tryptamines and beta-carbolines. A minireview. J Psychoactive Drugs 1984; 16:347-58. [PMID: 6394730 DOI: 10.1080/02791072.1984.10472305] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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McKenna DJ, Towers GH, Abbott F. Monoamine oxidase inhibitors in South American hallucinogenic plants: tryptamine and beta-carboline constituents of ayahuasca. JOURNAL OF ETHNOPHARMACOLOGY 1984; 10:195-223. [PMID: 6587171 DOI: 10.1016/0378-8741(84)90003-5] [Citation(s) in RCA: 237] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Ayahuasca is a hallucinogenic beverage derived by boiling the bark of the Malpighiaceous liana Banisteriopsis caapi together with the leaves of various admixture plants, viz. Psychotria viridis, Psychotria carthagenensis , or Diplopterys cabrerana . B. caapi contains harmine, harmaline, and tetrahydroharmine while the admixtures contain N,N-dimethyltryptamine (DMT). DMT, a potent hallucinogen, is inactive orally due to degradation by visceral monoamine oxidase (MAO). The beta-carbolines, however, are highly active reversible inhibitors of MAO and may protect the DMT from deamination by MAO and render it orally active. This mechanism has been proposed to underlie the oral activity of ayahuasca but has not been experimentally confirmed. In the present study the constituents of the admixture plants and the alkaloids of eight ayahuasca samples from Peru were qualitatively and quantitatively analyzed using two-dimensional thin-layer chromatography (TLC), high pressure liquid chromatography (HPLC) and gas chromatography/mass spectrometry (GC/MS). Several B. caapi cultivars were quantitatively compared for variations in alkaloid content. Three admixture plants used rarely in the manufacture of ayahuasca were also screened for alkaloids. A selected sample of beta-carbolines were screened for activity as MAO inhibitors using an in vitro assay system, and structure/activity relationships were compared. Inhibition observed with single compounds was compared with the activity of selected samples of ayahuasca which were screened in the system and also with the activity of mixtures of beta-carbolines. The levels of DMT and beta-carbolines found in the ayahuasca samples examined in the present study were an order of magnitude greater than the levels reported in a previous study. Ayahuasca was found to be an extremely effective inhibitor of MAO in vitro and the degree of inhibition was directly correlated with the concentration of MAO-inhibiting beta-carbolines. Inhibition experiments using mixtures of beta-carbolines indicated that their effects in combination are additive, rather than synergistic or antagonistic. Implications of the results in understanding the pharmacology of ayahuasca are discussed.
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Abstract
Monoamine oxidase (MAO) in astroglial primary cultures increased during cell development. The enzyme activity towards type B substrate was further enhanced in cultures treated with 0.25 mM dibutyl cyclic AMP (dBcAMP), although dBcAMP (1 mM) does not effect MAO activity in vitro. It has been estimated that the dBcAMP treated cultures contain 70% type A and 30% type B MAO, while in the untreated one, there was virtually only type A MAO. Following the application of Percoll density gradient centrifugation, MAO associated with different subcellular fractions was obtained. The dBcAMP treated fractions were slightly heavier than the untreated ones.
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Garrick NA, Murphy DL. Monoamine oxidase type A: differences in selectivity towards l-norepinephrine compared to serotonin. Biochem Pharmacol 1982; 31:4061-6. [PMID: 7159481 DOI: 10.1016/0006-2952(82)90656-6] [Citation(s) in RCA: 72] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
l-Norepinephrine and serotonin have been regarded as preferential substrates for monoamine oxidase (MAO) type A. A close comparative examination of a number of tissues from different species, however, indicated the following differences. Serotonin was a more selective substrate for MAO-A, being inhibited by low concentrations (less than 10(-7) M) of the irreversible MAO-A inhibitor, clorgyline, more consistently and to a greater extent (80-100%) than was l-norepinephrine (30-85%). These serotonin-norepinephrine differences were greater in humans and other primates than in rodents. Serotonin also had a 2- to 4-fold smaller apparent Km for MAO-A than l-norepinephrine and was deaminated 2- to 5-fold more readily by MAO in vitro in most tissues. In contrast, the MAO-B in human platelets deaminated l-norepinephrine more readily than serotonin. Thus, l-norepinephrine, like dopamine, should be regarded as a substrate for both MAO-A and MAO-B in vitro. The prominent role of MAO-B in norepinephrine degradation in primates may need to be considered in interpreting laboratory and clinical studies of clorgyline and other selective MAO-inhibiting drugs.
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23
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Yu PH, Hertz L. Differential expression of type A and type B monoamine oxidase of mouse astrocytes in primary cultures. J Neurochem 1982; 39:1492-5. [PMID: 6288878 DOI: 10.1111/j.1471-4159.1982.tb12598.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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24
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Campbell IC, Marangos PJ, Parma A, Garrick NA, Murphy DL. Localization of monoamine oxidases A and B in primate brains relative to neuron-specific and non-neuronal enolases. Neurochem Res 1982; 7:657-66. [PMID: 7121716 DOI: 10.1007/bf00965519] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Using serotonin and phenylethylamine deamination as measures of MAO A and MAO B activity respectively, positive correlations were observed between the activities of MAO A and MAO B in different areas of rhesus monkey and human brains. When the activities of MAO A and MAO B were compared with those of neuron-specific enolase and nonneuronal enolase (isozymes which are markers for neurons and glia), a slight but non-significant correlation was observed, suggesting that a simple distribution of MAO A in neurons and MAO B in glia is unlikely. This conclusion is supported by studies using synaptosomes, but contrasts with that from investigations of MAO from peripheral tissues, where experiments indicate that MAO A is predominantly localized in neurones.
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25
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Mazor M, Dvilansky A, Aharon M, Lazarovitz Z, Nathan I. Effect of cannabinoids on the activity of monoamine oxidase in normal human platelets. ARCHIVES INTERNATIONALES DE PHYSIOLOGIE ET DE BIOCHIMIE 1982; 90:15-20. [PMID: 6179486 DOI: 10.3109/13813458209082649] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Platelet MAO activity was affected by preincubation with cannabinoid derivatives in vitro. The psycho-active derivative delta 1-THC inhibited MAO activity in platelets to an extent varying according to its concentration while CBD and (+) delta 6-THC had no inhibitory effect. (-) delta 6-THC, which is minor psychomimetic component, had less inhibitory effect on MAO activity than delta 1-THC. However, (-) DMH delta 6-THC revealed no attenuation effect on MAO inspite of its well-known psychomimetic activity.
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Abstract
1. The characteristics of the electrical response to dopamine in the mouse neuroblastoma cell line N1E-115 were studied. 2. Neuroblastoma cells responded to ionophoretically applied dopamine by generating a transient depolarization. Under voltage-clamp conditions, a transient inward current was recorded in response to dopamine application. 3. The receptor was more effectively activated by dopamine than by noradrenaline. Haloperidol blocked the dopamine-induced current with an apparent dissociation constant of 40 nM. Phentolamine was much less potent than haloperidol, and propranolol had no effect. 4. The dopamine-induced current was increased in amplitude by hyperpolarizing the membrane, decreased by depolarization, and reversed its polarity at + 14 mV. 5. When the external sodium concentration was decreased from 125 to 94 mM, the reversal potential was shifted in the direction of hyperpolarization by 10 mV. 6. Increasing the external potassium concentration from 0.2 to 20 mM caused a shift of the reversal potential by 13 mV in the direction of depolarization. 7. Replacement of external chloride with isethionate or glutamate caused little or no shift in the reversal potential, but increased the amplitude of the current. 8. Increase in external calcium concentration caused a block of the dopamine-induced current with an apparent dissociation constant of 1.3 mM, without altering its reversal potential. 9. It is concluded that the ionic channel activated by dopamine undergoes a conductance increase to both sodium and potassium but not to chloride or calcium.
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27
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Bonnefil V, Castiglione CM, Cawthon RM, Breakefield XO. Effect of riboflavin on monoamine oxidase activity in cultured neuroblastoma cells. Cell Mol Neurobiol 1981; 1:351-9. [PMID: 6765737 DOI: 10.1007/bf00716270] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Monoamine oxidase (MAO) depends on a covalently attached FAD cofactor for activity. Activity is depressed in mouse neuroblastoma cells (N1E-115) grown in synthetic N2 medium lacking riboflavin. MAO activity in depleted cells is stimulated by added riboflavin, and this recovery is blocked by inhibitors of RNA and protein synthesis, and not by an inhibitor of protein glycosylation Recovery from riboflavin depletion appears to depend upon new RNA and protein synthesis, and not on the addition of FAD cofactor to an inactive MAO precursor.
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Affiliation(s)
- V Bonnefil
- Department of Human Genetics, Yale University School of Medicine, New Haven, Connecticut 06510
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28
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Nagy J, Salach JI. Identity of the active site flavin-peptide fragments from the human "A"-form and the bovine "B"-form of monoamine oxidase. Arch Biochem Biophys 1981; 208:388-94. [PMID: 7259196 DOI: 10.1016/0003-9861(81)90523-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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29
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Rittenhouse HG, Seguin EB, Fisher SK, Agranoff BW. Properties of a CDP-diglyceride hydrolase from guinea pig brain. J Neurochem 1981; 36:991-9. [PMID: 6110708 DOI: 10.1111/j.1471-4159.1981.tb01691.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Enzymatic hydrolysis of the pyrophosphate bond of CDP-diglyceride (CDP-DG), previously shown to occur in bacteria, is demonstrable in mammalian tissues. Activity was enriched in a lysosomal fraction obtained from guinea pig cerebral cortex and was purified 92-fold relative to the homogenate by a combination of XM-300 ultrafiltration and DEAE-cellulose column chromatography. When incubated with CDP-dipalmitin, the purified enzyme produced stoichiometric amounts of CMP and phosphatidate. dCDP-DG served as a substrate, while ADP-DG was an inhibitor, as were 5'-AMP and 5'-dAMP. CDP-DG hydrolysis was not affected by the presence of excess amounts of CDP-choline, CDP-glycerol, sodium pyrophosphate, or cyclic 3',5'-AMP.
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30
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Hawkins M, Wallace DC, Eisenstadt JM, Breakefield XO. Expression of monoamine oxidase A and B activities in mouse cybrids and hybrids. Life Sci 1981; 28:425-32. [PMID: 7219055 DOI: 10.1016/0024-3205(81)90089-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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31
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Fowler CJ, Norqvist A, Oreland L, Saramies E, Wiberg A. Monoamine oxide activity in ox, elk and reindeer brains. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. C: COMPARATIVE PHARMACOLOGY 1981; 68C:145-9. [PMID: 6112098 DOI: 10.1016/0306-4492(81)90008-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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32
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Castro Costa MR, Edelstein SB, Castiglione CM, Chao H, Breakefield XO. Properties of monoamine oxidase in control and Lesch-Nyhan fibroblasts. Biochem Genet 1980; 18:577-90. [PMID: 7437013 DOI: 10.1007/bf00484403] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Monoamine oxidase activity of the A type was measured in homogenates of cultured human skin fibroblasts. Twenty-four control lines had activities ranging over fifty-fold with an apparent bimodal distribution. Activity in fibroblasts from 20 patients with the Lesch-Nyhan syndrome fell in the low portion of the normal distribution with a mean activity about 50% that of the control mean (p < 0.05). In a subgroup of control and Lesch-Nyhan lines with levels of enzyme activity from 0.9 to 179 pmol/min/mg protein, monoamine oxidase was similar with respect to apparent Km for tryptamine, thermal stability at 56 C, and sensitivity to clorgyline. Thus the lower mean levels of activity observed in the Lesch-Nyhan as compared to control fibroblasts were not associated with other altered properties of the enzyme. The bimodal distribution of enzyme activity suggests that a genetic polymorphism for monoamine oxidase may control levels of activity expressed in fibroblasts.
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33
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Suzuki O, Hattori H, Oya M, Katsumata Y. Characteristics of monoamine oxidase in mitochondria isolated from chick brain, liver, kidney and heart. Biochem Pharmacol 1980; 29:603-7. [PMID: 7370053 DOI: 10.1016/0006-2952(80)90383-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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34
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Garrick NA, Murphy DL. Species differences in the deamination of dopamine and other substrates for monoamine oxidase in brain. Psychopharmacology (Berl) 1980; 72:27-33. [PMID: 6781004 DOI: 10.1007/bf00433804] [Citation(s) in RCA: 141] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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35
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Nahrwold ML, Hess WH, Bethell DR. Halothane and γ-aminobutyric acid in cultured cells of nervous system origin. Brain Res Bull 1980. [DOI: 10.1016/0361-9230(80)90076-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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36
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Meltzer HY, Arora RC. Distribution of type A and type B monoamine oxidase activities in rat and chicken skeletal muscle and nerves. Biochem Pharmacol 1979; 28:3261-4. [PMID: 526332 DOI: 10.1016/0006-2952(79)90119-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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37
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Murphy DL, Lipper S, Slater S, Shiling D. Selectivity of clorgyline and pargyline as inhibitors of monoamine oxidases A and B in vivo in man. Psychopharmacology (Berl) 1979; 62:129-32. [PMID: 111275 DOI: 10.1007/bf00427125] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
During 4 weeks of treatment with clorgyline, a selective MAO-A inhibitor, platelet monoamine oxidase (MAO) activity was unchanged. During a similar 4-week crossover treatment period with pargyline, a selective MAO-B inhibitor, platelet MAO activity was essentially completely inhibited in the same individuals. The differential effects of the two drugs on platelet MAO, which consists exclusively of the MAO-B form, suggests that the in vitro selectivity of clorgyline, and possibly of pargyline, on MAO-A and MAO-B may be maintained in vivo during long-term administration in man. Reductions in blood pressure, heart rate, and plasma amine oxidase activity were generally similar in magnitude during treatment with both drugs, however, suggesting that either these effects are nonspecific consequences of both MAO-A and MAO-B inhibition, or that pargyline also inhibited MAO-A activity.
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38
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Murphy DL, Redmond DE, Garrick N, Baulu J. Brain region differences and some characteristics of monoamine oxidase type A and B activities in the vervet monkey. Neurochem Res 1979; 4:53-62. [PMID: 109783 DOI: 10.1007/bf00963831] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Monoamine oxidase in the vervet monkey showed greater variations in activity in six brain regions when tyramine or phenylethylamine was used as the substrate (3.8- to 4.1-fold differences) than when serotonin was the substrate (1.8-fold differences). With phenylethylamine and tyramine as substrates, the highest MAO specific activities were found in the hypothalamus and the lowest in the cerebellum and cortex. With serotonin as the substrate, the highest specific activities were in the mesencephalon and cortex. The inhibition of tyramine deamination by clorgyline and deprenyl yielded biphasic plots indicative of the presence of MAO-A and MAO-B enzyme forms in the vervet brain. On the basis of these inhibitor curves, the vervet brain could be estimated to contain approximately 85% MAO-B and 15% MAO-A, in contrast to rat brain which contains 45% MAO-B and 5% MAO-A. The inhibition of serotonin deamination by deprenyl in vervet brain yielded a biphasic plot, suggesting that some serotonin deamination in the vervet is accomplished by the MAO-B enzyme form. Estimations of the relative amounts of MAO-A and MAO-B based on inhibitor curves or based on substrate ratios yielded proportionate results which were in close agreement across the different brain regions, supporting the validity of these approaches to estimating MAO-A and MAO-B activities.
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39
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40
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Castro Costa MR, Breakefield XO. Distinct forms of monoamine oxidase expressed in hepatoma and HeLa cells in culture. Biochem Pharmacol 1979; 28:525-8. [PMID: 426872 DOI: 10.1016/0006-2952(79)90246-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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41
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Campbell IC, Shiling DJ, Lipper S, Slater S, Murphy DL. A biochemical measure of monoamine oxidase type A and B inhibitor effects in man. J Psychiatr Res 1979; 15:77-84. [PMID: 490428 DOI: 10.1016/0022-3956(79)90020-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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42
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Campbell IC, Robinson DS, Lovenberg W, Murphy DL. The effects of chronic regimens of clorgyline and pargyline on monoamine metabolism in the rat brain. J Neurochem 1979; 32:49-55. [PMID: 32233 DOI: 10.1111/j.1471-4159.1979.tb04508.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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43
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Edelstein SB, Castiglione CM, Breakfield XO. Monoamine oxidase activity in normal and Lesch-Nyhan fibroblasts. J Neurochem 1978; 31:1247-54. [PMID: 702170 DOI: 10.1111/j.1471-4159.1978.tb06249.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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44
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45
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Suzuki O, Takanohashi M, Katsumata Y, Oya M. Multiple forms of monoamine oxidase in human brain tumors. Neurosci Lett 1978. [DOI: 10.1016/0304-3940(78)90190-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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46
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Richelson E. Desensitisation of muscarinic receptor-mediated cyclic GMP formation by cultured nerve cells. Nature 1978; 272:366-8. [PMID: 204871 DOI: 10.1038/272366a0] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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47
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Murphy DL. Substrate-selective monoamine oxidases--inhibitor, tissue, species and functional differences. Biochem Pharmacol 1978; 27:1889-93. [PMID: 361047 DOI: 10.1016/0006-2952(78)90001-1] [Citation(s) in RCA: 135] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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48
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Roth JA, Venter JC. Predominance of the B form of monoamine oxidase in cultured vascular intimal endothelial cells. Biochem Pharmacol 1978; 27:2371-3. [PMID: 728189 DOI: 10.1016/0006-2952(78)90147-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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49
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50
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Murphy DL, Donnelly CH, Richelson E, Fuller RW. N-substituted cyclopropylamines as inhibitors of MAO-A and -B forms. Biochem Pharmacol 1978; 27:1767-9. [PMID: 708457 DOI: 10.1016/0006-2952(78)90554-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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