The effect of 4-aminopyrazolo(3,4-d) pyrimidine on mouse plasma alpha-amylase activity.

A single dose of 4-aminopyrazolo(3,4-d) pyrimidine (4APP), an adenine analog, was orally administered at various concentrations of groups of mice and after 24 h, the plasma-alpha-amylase activity and cholesterol levels had significantly decreased in a dose-dependent manner. There was no change, however, in pancreatic superoxide dismutase activity or the lipid peroxide level. Histologically, zymogen degranulation was found after a high oral dose of 4APP (175 mg/kg). The same decrease in alpha-amylase activity occurred in mice that had received ip administration of 4APP, and in mice that were pretreated with dimethyl sulfoxide. Based on these results, it appears that 4APP decreases plasma alpha-amylase activity dose-dependently, possibly by pancreatic injury, and that free radicals play no part in the observed changes.