Proteolytic activity in duodenal juice in infants, children, and adults.

The capacity of duodenal juice to hydrolyse casein to trichloroacetic acid-soluble peptides 
was investigated: in a control group (11 infants and children and 
7 adults); in 5 children with pancreatic disease; in 10 children 
with enterogenic malabsorption (coeliac disease and cow's milk protein intolerance). The 
proteolytic activity per ml duodenal juice in fasting condition was as 
great in healthy infants and children as healthy adults (500-600 mg 
casein/ml/hour). There was a good correlation between trypsin content and proteolytic 
activity of duodenal juice. In pancreatic insufficiency, the proteolytic activity was 
extremely low (not measurable in 3 patients) as was the trypsin 
activity whereas in enterogenic malabsorption, it was within the ranges of 
the controls. 