Figure 1.

Dose-dependent inhibition of H,K-ATPase activity by ML 3000 (A) and by omeprazole (B). (A). Gastric microsomes suspended in ATPase assay buffer at pH 7.4 were incubated for 30 min with varying concentrations of ML 3000 and ATPase activity was then measured at pH 7.4. The half-maximal inhibitory concentration (IC₅₀) for ML 3000 was 16.4 μM (CI = 6.84–39.3 μM). (B). Gastric microsomes suspended in ATPase assay buffer at pH 6.1 were incubated for 30 min with varying concentrations of omeprazole, and then transfered to standard ATPase assay buffer at pH 7.4 for ATPase activity measurement. The IC₅₀ for omeprazole was 1.1 μM (CI = 0.26 – 11.3 μM). The data-points show mean ± s.e. from three independent assays in each of which SCH28080-sensitive ATPase activity was measured in triplicate.