Pancreatic lysosomal hydrolases in acute experimental pancreatitis in dogs

Abstract

Majority of literature data support the significance of proteases activation in pathogenesis of acute pancreatitis. The ability of cathepsins to the activation of trypsinogen was shown and the labilization of lysosomes of pancreas in different models of acute experimental pancreatitis (AEP) was reported. In present work the dynamic of lysosomal changes during the course of AEP in dogs is evaluated. AEP was induced in 17 mongrel dogs by Elliot's method. Six healthy dogs served as a control group (I). Pancreatitic dogs were killed after 6 hr (G. II, n = 5), after 12 hrs (G. III, n = 5), and after 24 hrs (G. IV, n = 6 survivors). The pancreata were removed and divided into segments A (less advanced changes, [B] most advanced changes) and C (intermediate changes). The lysosomal enriched subfraction was isolated from the C segments at 15 000 X g for 20 min. The total (T) and free (F) activity of beta-glucuronidase (beta-G), acid phosphatase (AP), acid cathepsins (Cs) was estimated and the value F/T (relative free activity-r.f.a.) was calculated as an index of lysosomal stability. The progressive increase of r.f.a. of hydrolases in whole homogenate and in lysosomal enriched subfraction depending on time of AEP was observed suggesting labilization of pancreatic lysosomes. This labilization was more expressed in corresponding parts of organ with more advanced pathological changes. The differences between part A and B were most evident after 6 hrs of AEP. The labilization of lysosomes is more pronounced after 12 and 24 hrs than after 6 hrs in analogical parts of organ. These results indicate that labilization of lysosomes in pancreas correspond to the degree of pathological changes of pancreatic tissue.