Pancreatic ductal and interstitial pressures in cats with chronic pancreatitis.

We investigated the etiology of interstitial hypertension in chronic pancreatitis by examining the relationship between pancreatic ductal and interstitial pressures in cats. The main pancreatic duct was cannulated in the tail of the gland and perfused at 1, 2, or 5 ml/hr, to simulate pancreatic secretion. Intraductal and interstitial pressures were measured in four groups of animals: (1) normal cats; (2) normal cats after acutely narrowing the main duct to 25% of its original diameter; (3) normal cats after encasing the body and tail in a rigid latex capsule; and (4) cats with chronic pancreatitis created by narrowing the main duct five weeks earlier. Duct perfusion increased intraductal pressure in all of the cats, but significantly more in groups 2, 3, and 4 compared to group 1. Pancreatic interstitial pressure was unchanged by duct perfusion in groups 1 and 2, but increased in groups 3 and 4. We concluded that the compliant tissue of the normal pancreas expanded to effectively dissipate the increase in duct pressure associated with duct perfusion. In chronic pancreatitis, the inelastic parenchyma and capsule limited the distensibility of the gland, which resulted in elevated interstitial pressures during duct perfusion.