The effect of hypovolemic shock on pancreatic secretion.

A vascular pathogenesis of pancreatitis has been postulated in diabetics, the aged, Ortner's Syndrome, and various low-flow states. This report studies canine pancreatic secretion in a preparation of hypovolemic shock produced by controlled hemorrhage maintained for varying durations. Pancreatic secretion was collected by cannulation of the main pancreatic duct in anesthetized dogs. Secretin was administered by continuous intravenous (i.v.) infusion of 4 U/kg/h. Four 15-min samples of pancreatic juice were collected. Then the dogs were bled by arterial line withdrawing 25-30% of total blood volume or until the mean blood pressure dropped to about 60 mmHg. Blood was collected in heparinized containers for reinfusion. Blood samples for amylase and 15-min samples of pancreatic juice for volume, bicarbonate, and enzymes were obtained during hypovolemia as well as during and following restoration of the blood volume. Hypovolemia induced significant decreases in pancreatic flow, bicarbonate and amylase secretion, parameters which increased after reinfusion but never returned to pre-shock levels. Increasing the period of hypovolemia increased the inhibition of pancreatic flow, increased blood amylase elevation, and resulted in visible pancreatic edema. We conclude that pancreatic secretion is diminished by hypovolemia, that this is initially reversible when hypovolemia is brief, but that the disturbance of function progresses to inflammatory pathology when hypovolemia is prolonged.