AN EXPERIMENTAL STUDY ON PANCREATIC FIBROSIS AND COLLAGENASE ACTIVITY FOLLOWING ACUTE PANCREATITIS

Abstract

This study was designed to elucidate a relationship between fibrous proliferation and collagenase activity in the pancreas following acute pancreatitis. Necrotizing pancreatitis was produced by a freezing procedure in the splenic segment of the pancreas of male Wistar rats. The freezed areas in the pancreas of these rats were studied at each time on histological changes, hydroxyproline levels determined by KISO method and collagenase activities detected by tissue culture method using neutral soluble collagen as substrate. The fibrous proliferation and hydroxyproline levels in the pancreatic tissue increased gradually after freezing procedure and reached to a peak of them at the 4th week. Following this, the both of them decreased with the lapse of time. The collagenase activities in the pancreatic tissue were found after 2 weeks, and 66.7% of the highest detection rate of the activity and grade 4 of the most intensive activity, exhibiting the lysis of almost all substrate, were recognized at the 5th week. These collagenase activities disappeared after 7 weeks. In examination using polyacrylamide gel disc electrophoresis, the purified collagen used as a substrate revealed 3 basic bands consisted of α, β and γ, and the substrate occurred the lyses by the pancreatic tissue showed further many bands separeted αA, βA and several degraded products.
From these findings, it is suggested that there is a close relationship between elevation of collagenase activity and fibrous change in the pancreas following necrotizing pancreatitis, and that collagenase activity plays an important role in dissolution and absorption of proliferated collagen fibers.