Lipase and colipase in canine pancreatic juice as etiologic factors in fat necrosis.

Lipase and colipase have been purified to homogeneity from canine pancreatic juice. The purity of the lipase and colipase preparations was established by acrylamide gel electrophoresis. Either lipase or colipase alone did not produce fat necrosis when injected intraperitoneally into mice. Fat necrosis was seen only when both lipase and colipase were used together. Selective removal of lipase from fresh canine pancreatic juice by immunoprecipitation with an antilipase specific antiserum also eliminated its fat necrotizing activity. Together, these results identify the fat necrotizing factors to be pancreatic lipase and colipase. Their uncontrolled release during acute pancreatitis is believed to constitute the cause of fat necrosis. The absolute amount of lipolytic activity was not found to be the crucial factor in the induction of fat necrosis. It is suggested that the colipase molecule may have other functions besides enhancing the lipolytic activity of purified lipase in causing fat cell necrosis.