Participarea colagenazei la biodegradarea colagenului în ficat în procesul de regresie a cirozei hepatice experimentale

Abstract

The role of the collagenase in the collagen degradation in rat liver during the regression of experimental cirrhosis has been investigated. The activity of collagenase has been determined biochemically and electronically and histochemically in the normal condition of liver and in CCl4 -induced fibrotic rat liver and during 2 months after the end of the treatment by CCl4 . In the condition of liver cirrhosis a decrease of collagenase activity has been revealed. After the cessation of CCl4 -treatment two maximums (on the 7th and 30th days) of a significant increase in collagenolytic activity have been determined. A strong correlation between the dynamics of collagenase activity and the change of hydroxyproline level in the liver tissue has been identified. Electronically and histochemically it has been determined that in a normal rat liver the active collagenase is located in lysosomes of .Kuppfer cells and endotheliocytes In the fibrotic rat liver the reaction product was revealed mainly extracellularly on hepatocytes, macrophages and fibroblasts cytolemma and on the adjacent collagen fibrils on the 7th and 30th days after CCl4 abolition. The results show that during the recovery from hepatic fibrosis the active collagenase is located mainly extracellularly. There are two periods of collagenolytical activity augmentation in liver – on the 7th and 30th days after the discontinuation of CCl4 -treatment. It means that the initiation of collagen degradation in liver takes place at least twice, probably, depending on the quantity and activity of different types of liver cells.