Gene/Protein
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Compound
Pivot Concepts:
Gene/Protein
Disease
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Drug
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Target Concepts:
Gene/Protein
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Query: UMLS:C0033377 (
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11,717
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Mice with a targeted disruption of the dopamine beta-hydroxylase (DBH) gene are unable to synthesize norepinephrine (NE) and epinephrine. These mice have elevated levels of dopamine in most tissues, although the levels are only a fraction of those normally found for NE. It is noteworthy that NE can be restored to normal levels in many tissues after a single injection of the synthetic amino acid precursor of NE, L-threo-3,4-dihydroxyphenylserine (DOPS). In other tissues, NE can be restored to normal levels after multiple injections of DOPS, whereas in the midbrain and cerebellum, restoration of NE is limited to 25-30% of normal. NE levels typically peak approximately 5 h after DOPS administration and are undetectable by 48 h. Epinephrine levels are more difficult to restore. The elevated levels of dopamine fall modestly after injection of DOPS. S(-)-Carbidopa, which does not cross the blood-brain barrier, inhibits
aromatic L-amino acid decarboxylase
and effectively prevents restoration of NE by DOPS in the periphery, while allowing restoration in the CNS.
Ptosis
and reductions in male fertility, hind-limb extension, postdecapitation convulsions, and uncoupling protein expression in dopamine beta-hydroxylase-deficient mice are all reversed by DOPS injection.
...
PMID:Restoration of norepinephrine and reversal of phenotypes in mice lacking dopamine beta-hydroxylase. 960 11
A 15-year-old Chinese male with infantile-onset hypotonia, developmental delay,
ptosis
, and oculogyric episodes presented with a history of chronic diarrhoea since the age of 5 years. At presentation, he had an exacerbation of diarrhoeal symptoms resulting in dehydration and malnutrition with a concurrent severe chest infection. In view of his infantile-onset hypotonia, oculogyric crises, and protracted diarrhoea, an autonomic disturbance related to neurotransmitters was suspected. Urine organic acid profiling was compatible with
aromatic L-amino acid decarboxylase
deficiency. The diagnosis was confirmed based on cerebrospinal fluid analysis and genetic mutation analysis. The patient was treated with a combination of bromocriptine, selegiline, and pyridoxine; a satisfactory reduction in diarrhoea ensued. Our report highlights the importance of urine organic acid screening in infantile-onset hypotonia, especially when accompanied by oculogyric crises, and severe diarrhoea which could manifest as a result of autonomic disturbance.
...
PMID:A rare cause of severe diarrhoea diagnosed by urine metabolic screening: aromatic L-amino acid decarboxylase deficiency. 2471 72