Age-associated theophylline metabolic activity corresponds to the ratio of 1,3-dimethyluric acid to theophylline in mice

Yuko Kuroda, Kazuaki Taguchi, Yuki Enoki, Kazuaki Matsumoto, Seiji Hori, Junko Kizu

Research output: Contribution to journalArticle


Age is known as one of influencing factor for theophylline (TP)-metabolizing capacity. In a previous our study, the ratio of TP and its major metabolite 1,3-dimethyluric acid (DMU) in serum (DMU/TP) is a useful index to estimate TP-metabolizing capacity, and this value markedly increased by influencing factor, such as the history of smoking. However, it is unknown whether DMU/TP values in serum reflect age-associated changes of TP-metabolizing capacity. In this study, the effect of age on the DMU/TP values in serum were investigated using mice of different age due to the limited blood sampling in human. The concentrations of TP and its metabolites in mouse serum were simultaneously measured using HPLC. As observed in human serum, serum TP concentrations were closely correlated with DMU concentration in mice, which indicates that the DMU/TP ratio is a good indicator of TP metabolic ability in mice. When TP was administered subcutaneously in 2?8-week-old mice, age-associated changes in the DMU/TP ratio in mice were observed. In conclusion, age-associated changes in TP-metabolizing capacity can be estimated by the DMU/TP ratio in serum.

Original languageEnglish
Pages (from-to)1423-1427
Number of pages5
JournalBiological and Pharmaceutical Bulletin
Issue number8
Publication statusPublished - 2019 Jan 1



  • 1,3-dimethyluric acid
  • Age
  • Individual medication
  • Theophylline

ASJC Scopus subject areas

  • Pharmacology
  • Pharmaceutical Science

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