Abstract
The addition of 8-bromo cyclic AMP, forskolin, theophylline, and 3-isobutyl-1-methylxanthine to the medium of PC 12 cells resulted in an increase in GTP cyclohydrolase I activity, but had no effect on dihydropteridine reductase activity, except theophylline which caused a decrease in dihydropteridine reductase activity at 96 h. GTP cyclohydrolase I activity peaked at 24 h and returned to normal 96 h after drug treatment. Cycloheximide decreased GTP cyclohydrolase I activity at 48 and 96 h, but had little effect on dihydropteridine reductase activity. The addition of reserpine selectively increased only GTP cyclohydrolase I activity. The addition of tetrahydrobiopterin and sepiapterin, however, coordinately inhibited both GTP cyclohydrosase I and dihydropteridine reductase activities. It appears that GTP cyclohydrolase I activity in PC 12 cells is regulated by cyclic AMP stimulation and by end-product inhibition, whereas dihydropteridine reductase activity is only subject to pterin inhibition.
Original language | English (US) |
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Pages (from-to) | 119-126 |
Number of pages | 8 |
Journal | Journal of Enzyme Inhibition and Medicinal Chemistry |
Volume | 3 |
Issue number | 2 |
DOIs | |
State | Published - 1989 |
Externally published | Yes |
Keywords
- Cyclic AMP
- Dihydropteridine reductase
- GTP cyclohydrolase
- PC 12
- Pheochromocytoma
- Tetrahydrobiopterin
ASJC Scopus subject areas
- Pharmacology
- Drug Discovery