On the source of lipase activity in gastric contents.

--A convenient assay procedure for determination of the activity of pharyngeal lipase (gastric content lipase), using a long chain triglyceride as substrate, is described. Lipase activity in extracts of rat tongue, salivas collected from the upper esophageal pouch from two human newborns with congenital esophageal atresia and in gastric content obtained from an infant with pyloric stenosis were studied. Optimal lipase activities of the three enzyme sources were found in the same pH-range. During hydrolysis the composition of the products formed were also similar. The data presented indicate that at least some of the lipase activity which is responsible for lipolysis in the stomach of the newborn, originates in pregastric tissues.