Pancreatic excretion test and barrier hypothesis in progression of chronic pancreatitis

Simultaneous data of the pancreozymin-secretin test and the pancreatic excretion test with 5,5-dimethyl-2,4-oxazolidinedione DMO) were reported for 50 patients with chronic pancreatitis. The pancreozymin-secretin test was abnormal in 90% of the patients, while the pancreatic DMO excretion test showed abnormality in 100% of the patients. The dynamic process of pancreatic excretory dysfunction is discussed. Over 60% of patients with low to moderate grade chronic pancreatitis showed a discordant pattern of decreased DMO output with normal bicarbonate concentration or normal volume flow. Approximately 96% of patients with advanced grade chronic pancreatitis had a excretory pattern of decreased DMO output with low bicarbonate concentration and decreased volume flow. These findings may further develop a barrier hypothesis in chronic pancreatitis. In the early stage of chronic pancreatitis, when functional capacity of the duct is preserved fairly well, the extraductal barrier to the rapid DMO diffusion into the ducts (diffusion barrier) may be primarily responsible for impaired pancreatic DMO excretion. With progression of chronic pancreatitis, the intraductal barrier (outflow barrier) may become pronounced and precipitate pancreatic excretory dysfunction for DMO. The concept of pancreatic barriers may well serve to systematize major histologic alterations observed in chronic pancreatitis.