Alterations of tetrahydrobiopterin biosynthesis and pteridine levels in mouse tissues during growth and aging

In the present study, we investigated age-related changes in pteridine reve ls and enzymatic activity responsible for tetrahydrobiopterin biosynthesis in mouse tissues. Until about 15 weeks after the birth, the remarkable chan ge of tetrahydrobiopterin (BH4) was observed in all tissues tested. Between 20 and 50 weeks after the birth, pteridines levels were almost constant in all of the tissues. Total biopterin levels were decreased and levels of pt erin and neopterin were increased in the period exceeding 50 weeks in all o f the tissues. Activities of guanosine triphosphate (GTP) cyclohydrolase I, pyrvoyltetrahydropterin synthase, and the production of BH4 were recognize d by specific biochemical assays, and we investigated the age-related chang es in mouse tissues. The alteration of these enzymatic activities was indic ated to be similar to that described in the change of pteridine levels. (C) 2000 Elsevier Science B.V. All rights reserved.