Determination of H+/K+-ATPase Activity in Human Gastric Biopsy Specimens

The aim of our work was to develop a method to determine the the H+/K+-ATPase activity of human gastric biopsy samples. Our method is based on the phosphatase activity and the K+-induceable property of the enzyme. K+-induceable pNPPase activity was determined from homogenated corpus and antrum biopsy samples. H+/K+-ase activity was calculated as the difference between the corpus and antrum K+-induceable pNPPase activities. Quality control measurements were done during 20 successive days from pooled homogenates. The total, between-day and between-run, within-day and within-run coefficients of variations were between 10 and 16%. The healthy mean and reference range of K+-induceable pNPPase activity in the corpus was 95.8 (95% CI: 83.4–108.2 mU/mg protein); in the antrum it was 28.3 (21.6–35.0) mU/mg protein. The calculated H+/K+-ATPase activity was 67.2 (56.9–77.5) mU/mg protein. The measured activities were independent of the age and gender. Summarizing our results we have concluded, that our novel method might be a potential tool to gather data about the functional acid producing capability of human gastric mucosa.