[A simple method of measuring ornithine decarboxylase activity in mixed human saliva]

A simple and sensitive method for measuring ornithine decarboxylase in mixed human saliva is described, based on assessing the waste of the reaction substrate ornithine by modified Chinard's color reaction. The highest specific activity of the enzyme (up to 1.5 ncat/ml) is found in salivary samples collected on an empty stomach in the morning. After centrifugation of the saliva the entire ornithine decarboxylase activity is localized in the mucin sediment.