Preliminary evaluation of an improved enzymatic assay method for measuring potassium concentrations in serum

Eri Ota, Shin ichi Sakasegawa, Shigeru Ueda, Kenji Konishi, Masaru Akimoto, Takiko Tateishi, Miki Kawano, Eisaku Hokazono, Yuzo Kayamori

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Background: K+ has important physiological functions. K+ concentrations in serum are generally determined using ion-selective electrodes (ISEs), though measurement using reagents in aqueous medium is also useful. Methods: K+ concentrations were measured using recombinant inosine 5'-monophosphate dehydrogenase (IMPDH), which was activated only by K+ and NH4+. Exogenous NH4+ and endogenous NH4+ were eliminated using glutamine synthase. Results: Regression analysis of the enzymatic assay (y) vs. the ISE method (x) gave the following relation: y=1.03x+0.09 (n=54, Sy,x=0.06mmol/l). The linear range was up to 12mmol/l when 1U/ml IMPDH was used. Conclusion: Advantages of the proposed assay method are: (i) the measured range is wider than that of existing enzymatic methods; (ii) the conditions for K+ determination can be maintained constant, regardless of the amount of NH4+ in the analyte and reagents; and (iii) the elimination system is simpler because the recombinant IMPDH is stimulated by only K+ and NH4+ and is unaffected by biological materials.

Original languageEnglish
Pages (from-to)73-75
Number of pages3
JournalClinica Chimica Acta
Volume446
DOIs
Publication statusPublished - Jun 5 2015

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Clinical Biochemistry
  • Biochemistry, medical

Fingerprint Dive into the research topics of 'Preliminary evaluation of an improved enzymatic assay method for measuring potassium concentrations in serum'. Together they form a unique fingerprint.

  • Cite this

    Ota, E., Sakasegawa, S. I., Ueda, S., Konishi, K., Akimoto, M., Tateishi, T., Kawano, M., Hokazono, E., & Kayamori, Y. (2015). Preliminary evaluation of an improved enzymatic assay method for measuring potassium concentrations in serum. Clinica Chimica Acta, 446, 73-75. https://doi.org/10.1016/j.cca.2015.03.042