Renal Excretion of Pancreatic Enzyme in Dogs

Kwon, Sung Won; Wang, Chong Soon; Kim, Kyuag Hwan; Hong, Sa Suk

Abstract

It is generally accepted that in acute pancreatitis, the enzymes normally excreted by the pancreas are released from the disrupted parenchyma into the extraductal space and taken up by way of the lymphatics and capillaries. The enzymes in the blood stream may appear in high concentration in the serum. Therefore, serum amylase and lipase determinations has long been a mainstay in the diagnosis of acute pancreatitis and other pancreatic diseases. However, many investigators have claimed that the urinary output of amylase may be elevated more consistently in acute pancreatitis than in the serum concentration of either amylase or lipase, and urinary amylase measurement is a more sensitive reflection of the presence of pancreatitis and of its clinical course than is the measurement of serum amylase or lipase. Clinically, one of the ominous signs which may develop during the early course of acute pancreatitis is severe hypotension. But, no agreement has been reached among investigators as to the cause of the hypotension, although several investigators have implicated a blood volume deficiency resulting form inflammatory process, and hypercalcemia. Perhaps, the majority have attributed the hypotension to systemic effect of some of the pancreatic enzymes, especially trypsin. Nevertheless, the correction of these factors sometimes fail to restore a normal blood pressure clinically. The purpose of the present investigation was to observe the relationships between serum concentration and urinary output of pancreatic enzymes, and to determine the degree of hypotension resulting from the systemic administration of pancreatic enzymes. These experimental procedures, consisted of heteroinfusion of human pancreatic juice and homoinfusion of canine pancreatic emulsion intravenously, and pancreatic ductal ligation in dogs. Blood and urine samples for the enzyme analysis were collected serially thorough the femoral vein and ureteral catheter before and after the procedure. Blood pressure was measured consistently by the kymograph before and after infusion of pancreatic juice. Activities of amylase and lipase were determined by methods of Nelson and, Cherry and Crandall, respectively. The results obtained are summarized as follows; 1. Following intravenous infusions of pancreatic juice exogenously. serum and urine concentrations of amylase and lipase increased rapidly, but these enzymes decreased rapidly in urinary excretion and gradually in serum concentration. Urinary recovery of amylase was approximately 10% of the total infused amount of pancreatic juice at the end of 4 hours. 2. Following ligation of the pancreatic duct, the amylase and lipase levels of serum rose gradually and reached the maximum at 24-48 hours after ligation and then gradually fell. The output of these enzymes in the urine were relatively constant while serum enzymes were increased. 3. When the human pancreatic juice was infused, hypotension was pronounced, and it was deeper and more prolonged in hypotensive effect with infusion of highly concentrated juice in the enzyme activities. With human pancreatic juice, a more sustained hypotension occurred than was observed after infusion of canine pancreatic emulsion. As a result of this investigation, it is felt that the hypotension in acute pancreatitis is probably the result of pancreatic enzymes itself. 4. In postinfusion period, the urine volume was markedly decreased following hypotension, and the urine volume was increased following blood pressure to normal level. This suggests that urine volume may diminish resulting from transient acute renal failure due to hypotensive effect by pancreatic enzymes.