The effect of the dopamine agonist pergolide on tyrosine hydroxylase activity in rat striatal and limbic miniprisms in vitro: A model for the dopamine autoreceptor?

1986 ◽  
Vol 333 (4) ◽  
pp. 349-353 ◽  
Author(s):  
Arnold G. Vulto ◽  
Christopher J. Fowler
Keyword(s):  
Tyrosine Hydroxylase ◽  
Dopamine Agonist ◽  
Hydroxylase Activity ◽  
Dopamine Autoreceptor ◽  
Tyrosine Hydroxylase Activity

scholarly journals Tyrosine hydroxylase activity and extrinsic fluorescence changes produced by polyanions

1993 ◽  
Vol 295 (1) ◽  
pp. 189-194 ◽  
Author(s):  
L G Gahn ◽  
R Roskoski
Keyword(s):  
Enzyme Activity ◽  
Tyrosine Hydroxylase ◽  
Hydroxylase Activity ◽  
Bivalent Cation ◽  
Physiological Regulation ◽  
Tyrosine Hydroxylase Activity ◽  
Cell Enzyme ◽  
Reporter Group ◽  
Rna And Dna

The activity of tyrosine hydroxylase in vitro is affected by many factors, including pH, phosphorylation by several protein kinases, and polyanions. We investigated the activation of tyrosine hydroxylase by RNA or DNA (polyanions), using purified rat PC12 cell enzyme. RNA and DNA each increased tyrosine hydroxylase activity in the presence of subsaturating (125 microM) tetrahydrobiopterin at pH 6. RNA increased enzyme activity up to 6-fold with an EC50 of 3 micrograms/ml. RNA and DNA each increased tyrosine hydroxylase activity by decreasing the Km of the enzyme for tetrahydrobiopterin from 3 mM to 295 microM in the presence of 100 micrograms/ml RNA or 171 microM in the presence of 100 micrograms/ml DNA. We used the apolar fluorescent probe 8-anilino-1-naphthalenesulphonic acid (1,8-ANS) as a reporter group to provide the first evidence for changes in conformation related to changes in activity. At pH 6.0, 1,8-ANS bound to tyrosine hydroxylase and exhibited a characteristic fluorescence spectrum. At pH 7.2, both enzyme activity and fluorescence decreased. DNA or heparin (another polyanion) activated tyrosine hydroxylase and decreased fluorescence of the reporter group 30% at pH 6.0. This decrease suggests that these polyanions altered the conformation of tyrosine hydroxylase. The activating effects of polyanions were diminished at physiological pH (6.8-7.2) or in the presence of bivalent-cation salts (10 mM) or univalentcation salts (100 mM). These results suggest that polyanions play a minimal role, if any, in the physiological regulation of tyrosine hydroxylase activity.

Effects of morphine, in vitro and in vivo, on tyrosine hydroxylase activity in rat brain

1973 ◽  
Vol 22 (24) ◽  
pp. 3237-3246 ◽  
Author(s):  
Theodore J. Cicero ◽  
Carol E. Wilcox ◽  
Ben R. Smithloff ◽  
E.Robert Meyer ◽  
Lawrence G. Sharpe
Keyword(s):  
Tyrosine Hydroxylase ◽  
Rat Brain ◽  
Hydroxylase Activity ◽  
Tyrosine Hydroxylase Activity

scholarly journals Modification of tyrosine hydroxylase activity by chloral derived β-carbolines in vitro

2002 ◽  
Vol 81 (4) ◽  
pp. 814-819 ◽  
Author(s):  
Franz Riederer ◽  
Alexander Luborzewski ◽  
Ralf God ◽  
Gerhard Bringmann ◽  
Joachim Scholz ◽  
...  
Keyword(s):  
Tyrosine Hydroxylase ◽  
Hydroxylase Activity ◽  
Tyrosine Hydroxylase Activity
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