Figure 3.

Inhibition of H,K-ATPase activity by arachidonic acid (A) and prostaglandin E₂ (B). Gastric microsomes suspended in ATPase assay buffer at pH 7.4 were incubated for 30 min with varying concentrations of arachidonic acid or PGE₂ and ATPase activity was then measured at pH 7.4. IC₅₀ for arachidonic acid was 16.7 μM (CI = 8.9 – 31.5 μM), and the IC₅₀ for PGE₂ was 15 μM (CI = 3.96 – 57.3 μM). The data-points show mean ± s.e. from three independent assays in each of which SCH28080-sensitive ATPase activity was measured in triplicate.