In a previous communication1 we reported that salivary ptyalin is diminished in the aged. The present study was undertaken to determine the activity under fasting conditions of the enzymes in saliva, in gastric juice and in duodenal juice by several of the newer enzyme methods as well as to compare any further differences in enzyme activity between these various secretions in young and in old persons.
MATERIAL AND METHOD
A total of 61 subjects were tested, 29 of them being between 60 and 96 years of age and the remainder, 32, varying in age from 12 to 60 years. Normal subjects were tested, but most of the members of the older age group showed one or another of the infirmities of old age. Most of the old subjects were residents of a home for the aged. The younger group consisted of suitable clinical patients, interns and graduate students.The