MAOs are important in the breakdown of monoamines ingested in food, and also serve to inactivate monoamine neurotransmitters. Because of the latter, they are involved in a number of psychiatric and neurological diseases, some of which can be treated with monoamine oxidase inhibitors (MAOIs) which block the action of MAOs.[6]
Subtypes and tissue distribution
In humans there are two types of MAO: MAO-A and MAO-B.[7]
MAO-A appears at roughly 80% of adulthood levels at birth, increasing very slightly after the first 4 years of life, while MAO-B is almost non-detectable in the infant brain. Regional distribution of the monoamine oxidases is characterized by extremely high levels of both MAOs in the hypothalamus and hippocampal uncus, as well as a large amount of MAO-B with very little MAO-A in the striatum and globus pallidus. The cortex has relatively high levels of only MAO-A, with the exception of areas of the cingulate cortex, which contains a balance of both. Autopsied brains demonstrated the predicted increased concentration of MAO-A in regions dense in serotonergic neurotransmission, however MAO-B only correlated with norepinephrine.[8]
Other studies, in which the activities of MAO (not protein amounts) were examined in rat brain, revealed the highest MAO-B activity in the median eminence of hypothalamus. Dorsal raphe nucleus and medial preoptic area have relatively high MAO-B activity, but much lower than MAO-B activity in the median eminence.[9][10] Among cerebral endocrine glands, pineal gland has high MAO-B activity (its median value is lower than that for median eminence and higher than that for medial preoptic area).[10] Pituitary has the lowest level of MAO-B activity when compared with brain areas studied.[9]
Function
Monoamine oxidases catalyze the oxidative deamination of monoamines. In the first part of the reaction, cofactorFAD oxidizes the substrate yielding the corresponding imine which converts the cofactor into its reduced form FADH2. The imine is then non-enzymatically hydrolyzed to the corresponding ketone (or aldehyde) and ammonia. Oxygen is used to restore the reduced FADH2 cofactor back to the active FAD form. Monoamine oxidases contain the covalently bound cofactorFAD and are, thus, classified as flavoproteins. Monoamine oxidase A and B share roughly 70% of their structure and both have substrate binding sites that are predominantly hydrophobic. Two tyrosine residues (398, 435 within MAO-B, 407 and 444 within MAO-A) in the binding pocket that are commonly involved in inhibitor activity have been hypothesized to be relevant to orienting substrates, and mutations of these residues are relevant to mental health. Four main models have been proposed for the mechanism of electron transfer (single electron transfer, hydrogen atom transfer, nucleophilic model, and hydride transfer[12]) although there is insufficient evidence to support any of them.[13]
Both forms metabolize dopamine, tyramine, and tryptamine;[16] however, some evidence suggests MAO-B may not be responsible for a significant amount of dopamine degradation.[17]
Specific reactions catalyzed by MAO include:[18][19]
In fact, MAO-A inhibitors act as antidepressant and anti-anxiety agents, whereas MAO-B inhibitors are used alone or in combination to treat Alzheimer's disease and Parkinson's disease.[42] Some research suggests that certain phenotypes of depression, such as those with anxiety, and "atypical" symptoms involving psychomotor retardation, weight gain and interpersonal sensitivity respond better to MAO inhibitors than other classes of anti-depressant. However the findings related to this have not been consistent.[43] MAOIs may be effective in treatment resistant depression, especially when it does not respond to tricyclic antidepressants.[44]
Parasite interactions
Sleeping sickness - caused by trypanosomes - gets its name from the sleep disruption it causes in mammals. That sleep disruption is caused, at least in part, by trypanosomes' tendency to disrupt MAO activity in the orexin system.[45]
Animal models
There are significant differences in MAO activity in different species. Dopamine is primarily deaminated by MAO-A in rats, but by MAO-B in vervet monkeys and humans.[46]
Mice unable to produce either MAO-A or MAO-B display autistic-like traits.[47] These knockout mice display an increased response to stress.[48]
The genes encoding MAO-A and MAO-B are located side-by-side on the short arm of the X chromosome, and have about 70% sequence similarity. Rare mutations in the gene are associated with Brunner syndrome.[medical citation needed]
A study based on the Dunedin cohort concluded that maltreated children with a low-activity polymorphism in the promoter region of the MAO-A gene were more likely to develop antisocial conduct disorders than maltreated children with the high-activity variant.[56] Out of the 442 total males in the study (maltreated or not), 37% had the low activity variant. Of the 13 maltreated males with low MAO-A activity, 11 had been assessed as exhibiting adolescent conduct disorder and 4 were convicted for violent offenses. The suggested mechanism for this effect is the decreased ability of those with low MAO-A activity to quickly degrade norepinephrine, the synaptic neurotransmitter involved in sympathetic arousal and rage. This is argued to provide direct support for the idea that genetic susceptibility to disease is not determined at birth, but varies with exposure to environmental influences. However, most individuals with conduct disorder or convictions did not have low activity of MAO-A; maltreatment was found to have caused stronger predisposition for antisocial behavior than differences in MAO-A activity.[medical citation needed]
The claim that an interaction between low MAO-A activity and maltreatment would cause anti-social behavior has been criticized since the predisposition towards anti-social behavior could equally well have been caused by other genes inherited from abusive parents.[57]
A possible link between predisposition to novelty seeking and a genotype of the MAO-A gene has been found.[58]
A particular variant (or genotype), dubbed "warrior gene" in the popular press, was over-represented in Māori. This supported earlier studies finding different proportions of variants in different ethnic groups. This is the case for many genetic variants, with 33% White/Non-Hispanic, 61% Asian/Pacific Islanders having the low-activity MAO-A promoter variant.[59]
Aging
Unlike many other enzymes, MAO-B activity is increased during aging in the brain of humans and other mammals.[60] Increased MAO-B activity was also found in the pineal gland of aging rats.[10] This may contribute to lowered levels of monoamines in aged brain and pineal gland.[10][61]
^Edmondson DE, Mattevi A, Binda C, Li M, Hubálek F (August 2004). "Structure and mechanism of monoamine oxidase". Current Medicinal Chemistry. 11 (15): 1983–93. doi:10.2174/0929867043364784 (inactive 2024-04-05). PMID15279562.{{cite journal}}: CS1 maint: DOI inactive as of April 2024 (link)
^ abRazygraev AV, Arutjunyan AV (2007-09-01). "Monoamine oxidase activity in several structures of rat brain". Neurochemical Journal. 1 (3): 204–207. doi:10.1134/S1819712407030051. S2CID9550341.
^ abcdRazygraev AV, Taborskaya KI, Volovik KY, Bunina AA, Petrosyan MA (2016-04-01). "Monoamine oxidase activity in the rat pineal gland: Comparison with brain areas and alteration during aging". Advances in Gerontology. 6 (2): 111–116. doi:10.1134/S2079057016020120. S2CID88975594.
^Figure 11-4 in: Flower R, Rang HP, Dale MM, Ritter JM (2007). Rang & Dale's pharmacology. Edinburgh: Churchill Livingstone. ISBN978-0-443-06911-6.
^Vianello R, Repič M, Mavri J (2012-10-25). "How are Biogenic Amines Metabolized by Monoamine Oxidases?". European Journal of Organic Chemistry. 2012 (36): 7057–7065. doi:10.1002/ejoc.201201122.
^Kalgutkar AS, Dalvie DK, Castagnoli N, Taylor TJ (September 2001). "Interactions of nitrogen-containing xenobiotics with monoamine oxidase (MAO) isozymes A and B: SAR studies on MAO substrates and inhibitors". Chemical Research in Toxicology. 14 (9): 1139–62. doi:10.1021/tx010073b. PMID11559028.
^Tipton KF (November 2018). "90 years of monoamine oxidase: some progress and some confusion". J Neural Transm (Vienna). 125 (11): 1519–1551. doi:10.1007/s00702-018-1881-5. PMID29637260.
^Matthes S, Mosienko V, Bashammakh S, Alenina N, Bader M (2010). "Tryptophan hydroxylase as novel target for the treatment of depressive disorders". Pharmacology. 85 (2): 95–109. doi:10.1159/000279322. PMID20130443.
^Slominski A, Tobin DJ, Zmijewski MA, Wortsman J, Paus R (January 2008). "Melatonin in the skin: synthesis, metabolism and functions". Trends Endocrinol Metab. 19 (1): 17–24. doi:10.1016/j.tem.2007.10.007. PMID18155917.
^ abcdKawamura M, Eisenhofer G, Kopin IJ, Kador PF, Lee YS, Fujisawa S, et al. (March 2002). "Aldose reductase: an aldehyde scavenging enzyme in the intraneuronal metabolism of norepinephrine in human sympathetic ganglia". Auton Neurosci. 96 (2): 131–139. doi:10.1016/s1566-0702(01)00385-x. PMID11958479.
^Holt A (November 2018). "On the practical aspects of characterising monoamine oxidase inhibition in vitro". J Neural Transm (Vienna). 125 (11): 1685–1705. doi:10.1007/s00702-018-1943-8. PMID30374594.
^ abcdBenedetti MS, Dostert P (1994). "Contribution of amine oxidases to the metabolism of xenobiotics". Drug Metab Rev. 26 (3): 507–535. doi:10.3109/03602539408998316. PMID7924902.
^Ambroziak W, Maśliński C (April 1988). "Participation of aldehyde dehydrogenase in the oxidative deamination pathway of histamine and putrescine". Agents Actions. 23 (3–4): 311–313. doi:10.1007/BF02142573. PMID3394581.
^Watanabe M, Maemura K, Kanbara K, Tamayama T, Hayasaki H (2002). "GABA and GABA receptors in the central nervous system and other organs". Int Rev Cytol. International Review of Cytology. 213: 1–47. doi:10.1016/s0074-7696(02)13011-7. ISBN978-0-12-364617-0. PMID11837891.
^ abPang X, Tang C, Guo R, Chen X (May 2022). "Non-cytochrome P450 enzymes involved in the oxidative metabolism of xenobiotics: Focus on the regulation of gene expression and enzyme activity". Pharmacol Ther. 233: 108020. doi:10.1016/j.pharmthera.2021.108020. PMID34637840.
^ abStrolin Benedetti M, Dostert P, Tipton KF. "Contributions of monoamine oxidase to the metabolism of xenobiotics". In Gibson GG (ed.). Progress in Drug Metabolism. Vol. 11. pp. 149–174.
^Domino EF, Khanna SS (March 1976). "Decreased blood platelet MAO activity in unmedicated chronic schizophrenic patients". The American Journal of Psychiatry. 133 (3): 323–6. doi:10.1176/ajp.133.3.323. PMID943955.
^Schildkraut JJ, Herzog JM, Orsulak PJ, Edelman SE, Shein HM, Frazier SH (April 1976). "Reduced platelet monoamine oxidase activity in a subgroup of schizophrenic patients". The American Journal of Psychiatry. 133 (4): 438–40. doi:10.1176/ajp.133.4.438. PMID1267046.
^Meyer JH, Ginovart N, Boovariwala A, Sagrati S, Hussey D, Garcia A, et al. (November 2006). "Elevated monoamine oxidase a levels in the brain: an explanation for the monoamine imbalance of major depression". Archives of General Psychiatry. 63 (11): 1209–16. doi:10.1001/archpsyc.63.11.1209. PMID17088501.
^Domschke K, Sheehan K, Lowe N, Kirley A, Mullins C, O'sullivan R, et al. (April 2005). "Association analysis of the monoamine oxidase A and B genes with attention deficit hyperactivity disorder (ADHD) in an Irish sample: preferential transmission of the MAO-A 941G allele to affected children". American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics. 134B (1): 110–4. doi:10.1002/ajmg.b.30158. PMID15717295. S2CID24453719.
^Bussone G, Boiardi A, Cerrati A, Girotti F, Merati B, Rivolta G (1 October 2016). "Monoamine oxidase activities in patients with migraine or with cluster headache during the acute phases and after treatment with L-5-hydroxytryptophan". Rivista di Patologia Nervosa e Mentale. 100 (5): 269–74. PMID318025.
^Filic V, Vladic A, Stefulj J, Cicin-Sain L, Balija M, Sucic Z, et al. (February 2005). "Monoamine oxidases A and B gene polymorphisms in migraine patients". Journal of the Neurological Sciences. 228 (2): 149–53. doi:10.1016/j.jns.2004.11.045. PMID15694196. S2CID572208.
^Riederer P, Lachenmayer L, Laux G (August 2004). "Clinical applications of MAO-inhibitors". Current Medicinal Chemistry. 11 (15): 2033–43. doi:10.2174/0929867043364775. PMID15279566.
^Kristensson K, Nygård M, Bertini G, Bentivoglio M (June 2010). "African trypanosome infections of the nervous system: parasite entry and effects on sleep and synaptic functions". Progress in Neurobiology. 91 (2): 152–71. doi:10.1016/j.pneurobio.2009.12.001. PMID19995590. S2CID207406469.
^Garrick NA, Murphy DL (1980). "Species differences in the deamination of dopamine and other substrates for monoamine oxidase in brain". Psychopharmacology. 72 (1): 27–33. doi:10.1007/bf00433804. PMID6781004. S2CID30722852.
^ abGripois D, Moreteau B, Ramade F (March 1977). "Sur l'activité monoaminoxydasique du cerveau de Locusta migratoria dans les conditions normales et après intoxication par deux insecticides: le chlordiméform et la diéldrine" [Monoamine oxidase activity of the brain of Locusta migratoria in normal conditions and after intoxication by two insecticides: chlordimeform and dieldrin]. Comptes Rendus de l'Académie des Sciences, Série D. 284 (12): 1079–82. PMID406057. S2CID29861405.
^Razygraev AV, Arutiunian AV (2008). "[Pineal gland and brain structures monoamine oxidase activity in rats of different age]". Advances in Gerontology = Uspekhi Gerontologii (in Russian). 21 (3): 402–5. PMID19432173.
Bayu Airlangga Bayu Airlangga adalah seorang politikus asal Indonesia. Bayu Airlangga adalah putra dari mantan Kepala BPN Jawa Timur Gede Ariyuda. Bayu menikah dengan putri bungsu mantan Gubernur Jawa Timur Soekarwo yang bernama Kartika Prawitasari. Setelah menikah dengan anak Soekarwo, Bayu Airlangga langsung terjun ke dunia politik untuk mengikut jejak mertuanya. Ia gabung dengan Partai Demokrat dan duduk sebagai Ketua Muda Mudi Demokrat Jatim. Partai Demokrat membuat dirinya maju pada Pemilu …
Limnanthaceae Limnanthes douglasii Klasifikasi ilmiah Kerajaan: Plantae Divisi: Magnoliophyta Kelas: Magnoliopsida Ordo: Brassicales Famili: Limnanthaceae Genera lihat teks. Limnanthaceae adalah salah satu suku anggota tumbuhan berbunga. Menurut Sistem klasifikasi APG II suku ini dimasukkan ke dalam bangsa Brassicales, klad euRosidae II. Wikimedia Commons memiliki media mengenai Limnanthaceae. Pengidentifikasi takson Wikidata: Q131608 Wikispecies: Limnanthaceae APNI: 154228 EoL: 4285 EPPO: 1LIMF…
CangkringanKapanewonNegara IndonesiaProvinsiDaerah Istimewa YogyakartaKabupatenSlemanPemerintahan • PanewuEdi Harmana SH, M.HumPopulasi • Total- jiwaKode Kemendagri34.04.17 Kode BPS3404170 Luas- km²Desa/kelurahan- Cangkringan (Jawa: ꦕꦁꦏꦿꦶꦔ꧀, translit. Cangkringan) adalah sebuah kapanéwon di Kabupaten Sleman, Daerah Istimewa Yogyakarta, Indonesia. Kapanewon Cangkringan berada di sebelah Timur Laut dari Ibu kota Kabupaten Sleman. Jarak Ibu kota…
Géza IISegel kerajaan GézaRaja Hungaria dan KroasiaBerkuasa1141–1162Penobatan16 Februari 1141PendahuluBéla IIPenerusIstván IIIWaliIlonaInformasi pribadiKelahiran1130TolnaKematian31 Mei 1162 – 1130; umur -33–-32 tahunPemakamanBasilika SzékesfehérvárDynastyWangsa ÁrpádAyahBéla II dari HungariaIbuIlonaPasanganEuphrosyne dari KievAnakIstván IIIBéla IIIErzsébet, Adipati BohemiaPangeran GézaÁrpádOdolaIlona, Adipati AustriaMargitAgamaKatolik Roma Géza II (Hongaria: I…
Burung-madu Belukar Status konservasi Risiko Rendah Klasifikasi ilmiah Kerajaan: Animalia Filum: Chordata Kelas: Aves Ordo: Passeriformes Famili: Nectariniidae Genus: Anthreptes Spesies: A. singalensis Nama binomial Anthreptes singalensisGmelin, 1788 Burung-madu Belukar adalah spesies burung yang mempunyai paruh, berdarah panas, dan membiak dengan cara bertelur. Pengidentifikasi takson Wikidata: Q27075705 Wikispecies: Chalcoparia singalensis Avibase: 67A740A4B19F444D BirdLife: 22717626 eBir…
English rock band This article is about the music group. For other uses, see Kasabian (disambiguation). KasabianKasabian performing at iTunes Festival, Roundhouse London In 2014Background informationAlso known asSaracuseOriginLeicester, EnglandGenres Indie rock[1] alternative rock[2] electronica[3] electronic rock[4][5] space rock[6] Years active1997–presentLabels Columbia Sony RCA Members Sergio Pizzorno Chris Edwards Ian Matthews Tim Carter Pas…
Malaysian paramilitary unit This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.Find sources: General Operations Force – news · newspapers · books · scholar · JSTOR (April 2009) (Learn how and when to remove this template message) General Operations ForcePasukan Gerakan AmThe RMP General Operations Force Emblem.Active1 August 19…
Heads of the Federal District Head of Government of Mexico CityJefe de Gobierno de la Ciudad de MéxicoCurrent seal of the Head of Government OfficeCoat of Arms of Mexico CityIncumbentMartí Batressince June 16, 2023AppointerPopular voteTerm length6 years, non-renewableInaugural holderCuauhtémoc CárdenasFormationDecember 5, 1997Websitewww.cdmx.gob.mx (in Spanish) Politics of Mexico Federal government Constitution of Mexico(history) Human rights LGBT rights Law Abortion Labor Nationality C…
Zona Eksklusi Chornobyl (Ukraina: Зона відчуженняЧорнобильської АЕС) Zona Alienasi, Zona 30 kilometer Wilayah eksklusi dan Daerah bencana Gerbang masuk ke Zona Eksklusi Chornobyl pada pos pemeriksaan Dytyatky Nama resmi: Zona Alienasi Pembangkit Listrik Tenaga Nuklir Chornobyl Dinamai untuk: Pembangkit Listrik Tenaga Nuklir Chornobyl setelah bencana Negara Ukraina Oblasts Oblast Kiev, Oblast Zhytomyr Raion Raion Ivankiv (termasuk…
العلاقات الأوغندية الميانمارية أوغندا ميانمار أوغندا ميانمار تعديل مصدري - تعديل العلاقات الأوغندية الميانمارية هي العلاقات الثنائية التي تجمع بين أوغندا وميانمار.[1][2][3][4][5] مقارنة بين البلدين هذه مقارنة عامة ومرجعية للدولتين: وجه الم…
Radio station in Bakersfield, California KWACBakersfield, CaliforniaBroadcast areaBakersfield and VicinityFrequency1490 kHzBrandingTu Liga Radio 1490 AMProgrammingLanguage(s)SpanishFormatSports radioAffiliationsTUDN RadioLas Vegas Raiders Spanish Radio NetworkOwnershipOwnerLotus Communications(Lotus Bakersfield Corp.)Sister stationsKCHJKIWIKPSL-FMKQKZHistoryFirst air date1956 (1956)Former call signsKMAP (1956–61)Technical information[1]Licensing authorityFCCFacility ID35109ClassCP…
Queen consort of Poland Christiane Eberhardine of Brandenburg-BayreuthQueen consort of PolandGrand Duchess consort of LithuaniaTenure15 September 1697 – 1 September 1706Tenure1709 – 4 September 1727Electress consort of SaxonyTenure27 April 1694 – 4 September 1727Born(1671-12-19)19 December 1671BayreuthDied4 September 1727(1727-09-04) (aged 55)Pretzsch an der ElbeBurialSt. Nicholas Evangelical Church,Pretzsch an der ElbeSpouseAugustus II of PolandIssueAugustus III of PolandHouseHohenzo…
La pelote basque est un sport de démonstration aux Jeux olympiques de 1924 à Paris. C'était la deuxième fois que le sport a été inclus dans le programme olympique, Aux Jeux olympiques de 1900, qui ont également eu lieu à Paris, il était un sport olympique officiel. Les compétitions eurent lieu à la Porte de Billancourt. Les équipes de France et d'Espagne ont été les seules à participer. Résultats Épreuves Or Argent Bronze Cesta Punta H Sagrana, Garate, Santamaría Camino, Harizp…
مؤتمر سان فرانسيسكو تعديل مصدري - تعديل مؤتمر الأمم المتحدة للمنظمة الدولية (United Nations Conference on International Organization) أختصارا (UNCIO)، المعروف باسم مؤتمر سان فرانسيسكو (San Francisco Conference) كان اتفاقية بين مندوبين من 50 دولة من الحلفاء حيث جرى المؤتمر من 25 أبريل 1945 إلى 26 يونيو 1945 في سان فر…
Music and musical traditions of Cyprus This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.Find sources: Music of Cyprus – news · newspapers · books · scholar · JSTOR (December 2008) (Learn how and when to remove this message) Flute from Cyprus The music of Cyprus includes a variety of traditional, Western classical and Western …
French politician Aurélia Beigneux in 2014. Aurélia Beigneux (born 2 June 1980), is a French politician. Biography Born on 2 June 1980, she is a director of Epinorpa, a company founded in 2002.[1] Assistant for Social Affairs at the Town Hall of Hénin-Beaumont,[2] she was in fourteenth position on the list of the National Rally for the 2019 European elections and elected.[3][4] Beigneux has been targeted in a litigation case by the RSA CAF, after a distortion b…
Christopher Nolan reçoit l'Oscar du meilleur réalisateur pour son film Oppenheimer en 2024. L’Oscar du meilleur réalisateur (Academy Award for Best Director) est une récompense cinématographique américaine décernée chaque année, depuis 1929 par l'Academy of Motion Picture Arts and Sciences (AMPAS), laquelle décerne également tous les autres Oscars. Exception faite de la 1re cérémonie des Oscars, qui fut la seule fois dans l'histoire des Oscars où deux réalisateurs furent r…
2006 studio album by The ElectedSun, Sun, SunStudio album by The ElectedReleasedJanuary 24, 2006GenreIndie rockLength47:52LabelSub Pop[1]The Elected chronology Me First(2004) Sun, Sun, Sun(2006) Bury Me in My Rings(2011) Professional ratingsAggregate scoresSourceRatingMetacritic63/100[2]Review scoresSourceRatingAllMusic[3]Pitchfork Media6.8/10[4]PopMatters[5]Rolling Stone[6] Sun, Sun, Sun is the second album by indie band The Elected, relea…
هذه المقالة عن المجموعة العرقية الأتراك وليس عن من يحملون جنسية الجمهورية التركية أتراكTürkler (بالتركية) التعداد الكليالتعداد 70~83 مليون نسمةمناطق الوجود المميزةالبلد القائمة ... تركياألمانياسورياالعراقبلغارياالولايات المتحدةفرنساالمملكة المتحدةهولنداالنمساأسترالياب…