Activities of monoamine oxidase-A and -B are altered in the brains of congenitally hyperammonemic sparse-fur (spf) mice.
Activities of monoamine oxidases, MAOA and MAOB, were measured using radiometric assays in different brain regions of the sparse-fur (spf/Y) mouse, a model of congenital hyperammonemia resulting from an X-chromosomal defect of ornithine transcarbamylase. MAOA activities were decreased in cerebellum (by 23%, P < 0.05) and brainstem (by 16%, P < 0.05) of spf mice; activities of MAOB were concomitantly increased in cerebellum (by 22%, P < 0.05), brainstem (by 20%, P < 0.05) and cerebral cortex (by 22%, P < 0.05). These findings offer a rational explanation for previous findings of increased acidic metabolites of monoamines in the brain of spf mice. Altered monoaminergic function could be a key factor in the pathogenesis of neurological dysfunction in congenital hyperammonemias.
Rao
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Neuroscience Research Unit, André-Viallet Clinical Research Center (University of Montreal), Hopital Saint-Luc, Que., Canada.
Qureshi
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Butterworth
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D000641:Ammonia / Q000097:blood*; D000818:Animals; D001921:Brain / Q000201:enzymology*; D001923:Brain Chemistry / Q000502:physiology; D008297:Male; D008661:Metabolism, Inborn Errors / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008818:Mice, Neurologic Mutants; D008995:Monoamine Oxidase / Q000378:metabolism*; D009954:Ornithine Carbamoyltransferase / Q000235:genetics / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism
D012701:Serotonin; D000641:Ammonia; D008995:Monoamine Oxidase; D009954:Ornithine Carbamoyltransferase