Monoamine oxidase B

About: Monoamine oxidase B is a research topic. Over the lifetime, 2698 publications have been published within this topic receiving 86759 citations. The topic is also known as: Monoamine oxidase B.

Mapping human brain monoamine oxidase A and B with 11C-labeled suicide inactivators and PET.

Abstract: The regional distributions of monoamine oxidase (MAO) types A and B have been identified in human brain in vivo with intravenously injected 11C-labeled suicide enzyme inactivators, clorgyline and L-deprenyl, and positron emission tomography. The rapid brain uptake and retention of radioactivity for both 11C tracers indicated irreversible trapping. The anatomical distribution of 11C paralleled the distribution of MAO A and MAO B in human brain in autopsy material. The corpus striatum, thalamus, and brainstem contained high MAO activity. The magnitudes of uptake of both [11C]clorgyline and L-[11C]deprenyl were markedly reduced in one subject treated with the antidepressant MAO inhibitor phenelzine. A comparison of the brain uptake and retention of the 11C-labeled inactive (D-) and active (L-) enantiomers of deprenyl showed rapid clearance of the inactive enantiomer and retention of the active enantiomer within MAO B-rich brain structures, in agreement with the known stereoselectivity of MAO B for L-deprenyl. Prior treatment with unlabeled L-deprenyl prevented retention of L-[11C]deprenyl. Thus, suicide enzyme inactivators labeled with positron emitters can be used to quantitate the distribution and kinetic characteristics of MAO in human brain structures.

Beta-phenylethylamine: a specific substrate for type B monoamine oxidase of brain.

Abstract: β-Phenylethylamine and serotonin were oxidatively deaminated by separate forms of monoamine oxidase of rat brain wimen studied in vitro . These forms, designated as type A and type B enzyme, have different characteristics. For example, type A enzyme deaminated serotonin, was sensitive to the drug clorgyline, was resistant to the drug deprenyl and was heat-stable. In contrast, type B enzyme deaminated β-phenylethylamine, was resistant to clorgyline, was sensitive to deprenyl and was heat-labile. Moreover, type A and type B enzyme activities could be partially separated by centrifugation on a continuous sucrose gradient. β-Phenylethylamine and serotonin are present in mammalian brain. We conclude from our studies that the amines of brain may be cataboblized by specific types of monoamine oxidase in vivo .

X-linked borderline mental retardation with prominent behavioral disturbance: phenotype, genetic localization, and evidence for disturbed monoamine metabolism.

Abstract: We have identified a large Dutch kindred with a new form of X-linked nondysmorphic mild mental retardation All affected males in this family show very characteristic abnormal behavior, in particular aggressive and sometimes violent behavior Other types of impulsive behavior include arson, attempted rape, and exhibitionism Attempted suicide has been reported in a single case The locus for this disorder could be assigned to the Xp11-21 interval between DXS7 and DXS77 by linkage analysis using markers spanning the X chromosome A maximal multipoint lod score of 369 was obtained at the monoamine oxidase type A (MAOA) locus in Xp1123-114 Results of 24-h urine analysis in three affected males indicated a marked disturbance of monoamine metabolism These data are compatible with a primary defect in the structural gene for MAOA and/or monoamine oxidase type B (MAOB) Normal platelet MAOB activity suggests that the unusual behavior pattern in this family may be caused by isolated MAOA deficiency