ACTIVATION OF PANCREATIC PROTEOLYTIC ENZYMES BY COMMERCIAL COLLAGENASES

Abstract

Successful pancreatic islet cell transplantation using collagenase digestion is routinely accomplished with both autografts and isografts. Empirical control of the enzymatic digestion has been established by varying the size of minced tissue, the collagenase concentration, and the digestion time. The time required to reduce minced pancreatic tissue by commercial collagenase to small groups of cells is less than 1 h and, depending on collagenase concentration, may be less than 20 min. Chromatographically purified collagenases will not visibly digest minced pancreatic tissue after several hours. Digestion of pancreatic tissue is thus not entirely the result of the enzyme collagenase, but rather of the impurities inherent in the commercial product. Commercial collagenase contains inherent impurities that activate endogenous pancreatic proteolytic enzymes. These findings were studied using a general proteolytic enzyme substrate (BAEE [benzylarginine ethyl ester]) and canine pancreas.