Changes of the hepatic extracellular matrix during the healing of the focal liver injury

Abstract

The present study was undertaken to clear the changes of the hepatic extracellular matrix during the healing process of the focal injury in the rat liver by the light and electron immunohistochemical methods using anti type I, III, IV collagen, laminin and fibronectin serum.
One day after thrusting the heated needle into the rat liver, degenerated hepatocytes produced fibronectin. Two days after the injury, Ito cells began to produce type III, IV collagen and laminin, also endothelial cells began to produce type IV collagen and laminin. Four days after the injury, Ito cells produced type I collagen as well as type III, IV collagen and laminin, and also endothelial cells forming a capillary began to produce type III collagen. In this stage, connective tissue was formed by the extracellular matrix produced by hepatocytes, Ito cells and endothelial cells. Eight days after the injury, hepatocytes began to produce type III collagen, laminin and fibronectin. These results suggested that the extracellular matrix produced by hepatocytes, Ito cells, and endothelial cells plays an important role in the healing process of acute hepatic injury by the fire-heated needles.