Pancreatic pseudocyst fluid–a mixture of plasma proteins and pancreatic juice possessing a high proteolytic activity

Abstract

Pancreatic pseudocyst fluid from eight patients was examined biochemically. The fluid was found to be a mixture of plasma proteins and pancreatic juice, possessing a high proteolytic activity against high- as well as low-molecular-weight proteins. The proteolytic activity was found to be trypsin-, kallikrein-and plasmin-like. Gel filtration studies showed proteolytic activity to be present corresponding to alpha-2-macroglobulin-bound proteases and also to free proteases. Quantitative immunochemical levels were about 30-100% of normal plasma levels for alpha-2-macroglobulin, CI inhibitor, antithrombin III and alpha-2-antiplasmin. However, there was practically no functional inhibitory capacity left in the pseudocyst fluid, except for alpha-1-protease inhibitor, which retained its inhibitory capacity. Neither native kininogen nor complement factor C3 was found: this was probably a result of the proteolytic activity.

It is concluded, that a continuing proteolytic activity within the pseudocyst, although decreasing with aging of the cyst, could explain symptoms and complications caused by the pseudocyst.

Key Words:

• cyst aspiration
• fluid collections
• pancreatic cyst
• pancreatic disease
• protease inhibitors
• proteolysis
• proteolytic enzymes