Influence of an Aromatic Amino Acid Decarboxylase Inhibitor on GTP Cyclohydrolase I Activity in the Rat Brain

Hideo Sakamoto, Ko Fujita, Hiroshi Kuzuya
1997 Pteridines  
Based on the hypothesis that catecholamine decreases may cause increases in biopterin, we measured the GTP cyclohydrolase I(GTPCH-I) activity and biopterin content in the cerebral cortex, midbrain/diencephalon, cerebeilum, pons/medulla oblongata, striatum , and hippocampus of brains from rats given NSD-lOIS, an inhibitor for aromatic amino acid decarboxylase . The catecholamine contents decreased in all the regions tested. The changes in the GTPCH -I activity and bioptcrin content were
more » ... ntent were different among the regions; they decreased in some regions contrary to expectations and increased in other regions. However, either the enzyme activity or biopterin content increased in the midbrain/ diencephalon and pons/ medulla oblongata, in which similar levels of catecholamines, GTPCH -I activity and biopterin were detected. These results suggest that for the midbrain/diencephalon and pons/medulla oblongata the surmise that a decrease in catecholamines causes an increase in the biopterin synthesis may be correct.
doi:10.1515/pteridines.1997.8.3.206 fatcat:lep7bdivmvbexpcxiener2jhdu