Measurement of pancreatic enzyme synthesis in humans. Problems in patients with calcific pancreatitis.

Earlier studies have suggested that the rate of incorporation of labeled amino acids into duodenal juice proteins during pancreatic stimulation may be used to calculate pancreatic enzyme synthesis and function. In the present study, a pulse/4 h continuous intravenous infusion of 14C labeled leucine was used to compare synthesis rates in 6 patients with chronic calcific pancreatis(CP) to 4 controls. Analysis of duodenal juice protein demonstrated a delay of approximately 1 h in the appearance of labeled proteins, followed by a linear increase in specific activity, allowing calculation of synthesis that varied between 2.6-2.8 h in controls and 6-48 h in CP. The protein in controls was representative of enzyme protein, but that of CP was not, since it was heavily contaminated with albumin (up to 50%). The results indicate that enzyme secreted during the first hour of stimulation is derived from pancreatic stores and that the synthesis rate of enzymes secreted thereafter is approximately 2.7 h in normal humans. The method was, however, unable to determine rates in patients with CP owing to heavy contamination of enzymes with exudative proteins.