Induction of GTP cyclohydrolase I by bacterial lipopolysaccharide in the rat.
A 2- to 3-fold increase of GTP cyclohydrolase I (E.C. 3.5.4.16), the key enzyme of tetrahydrobiopterin biosynthesis from GTP, was observed in cerebellum, remaining brain, liver, spleen, and adrenal gland of rats treated with a single dose of lipopolysaccharide (LPS). This led to increased biopterin levels in tissues but not in plasma. Parallel induction of nitric oxide (NO) synthase was indicated by a 10- to 100-fold increase of plasma nitrate levels 6 and 12 hours after injection of LPS. Furthermore, systolic blood pressure was reduced significantly by 23%. Our results demonstrate induction of tetrahydrobiopterin biosynthesis after LPS treatment in vivo.
Werner-Felmayer
G
G
Institut für Medizinische Chemie und Biochemie, Universität Innsbruck, Austria.
Prast
H
H
Werner
E R
ER
Philippu
A
A
Wachter
H
H
D000818:Animals; D001708:Biopterins / Q000031:analogs & derivatives / Q000378:metabolism; D001794:Blood Pressure; D004790:Enzyme Induction; D006136:GTP Cyclohydrolase / Q000096:biosynthesis*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D009566:Nitrates / Q000097:blood; D009928:Organ Specificity; D051381:Rats; D017207:Rats, Sprague-Dawley
D008070:Lipopolysaccharides; D009566:Nitrates; D001708:Biopterins; D006136:GTP Cyclohydrolase; C003402:sapropterin