Short Communication

Abstract

Using adenosine 5'-monophosphate (Arkesteijn\ J. Clin. Chem. Clin. Biochem. 14 (1976) 155) and inosine 5'-monophosphate (Bertrand & Buret; Clin. Chim. Acta 119 (1982) 275) äs Substrates for the determination of serum 5 f -nucleotidase, linear Arrhenius plots were obtained between 25 °C and 37 °C. With the latter method, in patients with hepatobiliary disease, activation energy is higher than in healthy subjects (67.8 ± 0.8 kJ · mol" 1 vs. 59.2 ± 1.6 kJ -mol" 1 , p < 0.001). Neuraminidase treatment resulted in a significant reduction in the activation energy of serum 5'-nucleotidase from patients (63.6 ± 0.6 kJ · mol" 1 , p < 0.001). Although the activation energy seen is also influenced by conditions other than sialic acid content, the results obtained are in accordance with the hypothesis that in liver disease serum 5-nucleotidase becomes more sialylated.