Pancreatic vascular regulation in chronic pancreatitis in cats

In experimental obstructive chronic pancreatitis the normal hyperaemic response to secretory stimulation is lost, suggesting abnormal vascular regulation. Vascular regulatory mechanisms were investigated by observing the effect of increments in portal pressure on pancreatic blood flow in normal cats and cats with chronic pancreatitis. Normal cats maintained pancreatic blood flow until portal pressure was > 15 mm Hg, after which it decreased. Total vascular resistance decreased until the portal pressure was 15 mm Hg and increased thereafter. These observations suggested that metabolic regulatory mechanisms prevailed while portal pressure was in the physiological range but myogenic mechanisms became dominant during portal hypertension. In chronic pancreatitis the basal pancreatic blood flow was reduced and was inversely proportional to portal pressure. Total vascular resistance increased as portal pressure increased. In chronic pancreatitis myogenic regulatory responses prevailed at all levels of portal pressure. In conclusion, intrinsic regulation of pancreatic blood flow was abnormal in cats with chronic pancreatitis. The loss of the predominance of metabolic regulation over the normal range of portal pressure may partly explain the reduction of pancreatic blood flow in response to secretory stimulation.