pH and Pancreatic Enzymes in the Human Duodenum during Digestion of a Standard Meal

Abstract

Seventy-seven healthy subjects were given a standardized meal and the duodenal contents were aspirated during four consecutive periods of 20 minutes. The volume, pH, and the concentration of α-amylase, trypsin, chymotrypsin, and lipase of the aspirates were determined. The stabilities of the enzymes in the aspirates and the reproducibility of the procedures were recorded.

All results were statistically evaluated. Parameters were established for the different populations of pH, enzyme concentrations and relations of enzyme concentrations, and the corresponding normal ranges were defined (95 per cent probability). The variations in repeated tests in one subject were considerably smaller than those observed among different subjects. Hypochlorhydria was correlated with a higher duodenal pH. Male subjects with gastric acid secretion provided a pH which was lower than those obtained from female subjects. The concentrations of the enzymes reached the highest values in the first collection and remained constant at a lower level in the subsequent collections.

The results provide a basis for the evaluation of the exocrine function of the pancreas under physiological conditions.

Index-words::

• Pancreas
• duodenum
• enzymes
• enzyme tests
• digestion