A sensitive enzymatic assay for the determination of sucrose in serum and urine.

Background: Sucrose permeability has been suggested as a simple and non-invasive marker of gastric mucosal damage. We here report on a sensitive enzymatic assay using four sequential enzyme reactions coupled with reduced thio-NADPH.

Methods: Sucrose is phosphorylated by sucrose phosphorylase (EC2.4.1.7). The subsequent reaction in the presence of phosphoglucomutase (EC5.4.2.2) and glucose-1,6-diphosphate forms glucose-6-phosphate. Sucrose of the monad forms the dyad thio-NADPH. The reaction is monitored by changes in absorbance at 405 nm.

Results: The lower limit of detection (3SD method) was 2.8 micromol/l for serum and 7.0 micromol/l for urine. The precision of the method was <4.0%, and has sufficient analytical range.

Conclusions: The assay was sensitive enough to monitor serum sucrose concentrations during the sucrose permeability test and an automated assay may be useful in a large number of subjects.