Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:1.14.16.2 (
tyrosine hydroxylase
)
14,760
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
A low-molecular-weight component present in medium conditioned by cultured chick liver cells (
LCM
) enhances the adrenergic properties of dissociated chick superior cervical ganglion (SCG) neurons in culture (Zurn and Mudry, 1986). This substance cannot replace NGF as a survival, growth, or differentiation factor. However, in the presence of NGF, it stimulates neuronal metabolism and catecholamine (CA), but not ACh production by the SCG neurons. The effect on transmitter production is greater than that on neuronal metabolism. Yet this is not due to an increase in the specific activity of
tyrosine hydroxylase
(TH), the rate-limiting enzyme in CA synthesis. Interestingly, the effect of
LCM
on CA and ACh production, but not on neuronal metabolism, is potentiated in the presence of a large excess of NGF. The active component(s) present in
LCM
has a molecular weight lower than 500 Da and is not inactivated by heat or pronase treatment. So far, none of the small molecules tested (ascorbic acid, pyruvate, glucose, L-glutamic acid, glutathione, etc.) were able to mimic the effects of
LCM
on the SCG neurons. Thus this report describes a novel low-molecular-weight component different from NGF that promotes metabolism and adrenergic development in cultured chick sympathetic neurons.
...
PMID:A new low-molecular-weight component promoting adrenergic development in cultured chick sympathetic neurons. 289 Jul 20
1-methyl-4-phenyl-1,2,4,6,-tetrahydropyridine (MPTP) is a selective neurotoxin that produces striatal dopamine depletion resulting in parkinsonism like symptoms in humans and is, therefore, used to generate animal models for Parkinson's disease (PD). In this study, C57BL/6N mice were treated with MPTP acutely (3x20 mg/kg, 2-hour interval, one day injection). Mice were then sacrificed 24 hours after the last injection and brain tissue was collected for analysis. Significant decrease of striatal dopamine (DA) and the metabolites (DOPAC, HVA) was observed after MPTP treatment. MPTP also reduced protein expression of
tyrosine hydroxylase
(TH) in the striatum. Real time RT-PCR was used to examine selective genes of the dopaminergic system in the substantia nigra. Our data demonstrated that MPTP significantly decreased gene expression of TH, dopamine transporter (DAT), and vesicle monoamine transporter (VMAT), coinciding with the pattern of dopamine concentration changes and protein expression after MPTP treatment. Although a significant decrease of DA metabolites was observed in striatum, there was no change in the expression of monoamine oxidases (MAO-A, MAO-B) or catechol O-methyltransferase (COMT), indicating that these changes might be simply a consequence of reduced monoamine levels. In addition, gene expression of alpha-synuclein was also decreased with MPTP treatment, but there was no change in beta-synuclein and parkin. This is the first study using real-time PCR to indicate that MPTP selectively alters gene expression and provides information for clinical studies in PD. Future studies will focus on gene expression of other pathways that may be affected by MPTP treatment and investigation of gene expression in specific cell types in vivo using
LCM
technology.
...
PMID:Selective alterations of gene expression in mice induced by MPTP. 1549 5
