Abstract
Background: Aging is a gradual deterioration in the function of tissues and organ systems with loss of the ability to maintain homeostasis, due to structural alteration or dysfunction. Aging impact directly on all the different types of liver cells: hepatocytes, liver sinusoidal endothelial cells (LSECs), Küpffer cells (KCs) and hepatic stellate cells (HSCs). Activation of HSCs leads to deposition of collagen in the space of Disse, decrease of fenestrations of LSECs and formation of basement membrane. These changes called pseudocapillarization. Tenascin-C (TN-C) is an extracellular matrix glycoprotein markedly up-regulated during liver fibrosis. Tenascin-C is highly expressed during embryonic development, wound healing, chronic inflammation and cancer.
Aim of the study: we investigated the contribution of TNC to liver pseudocapillarization by comparing expression of tenascin c and levels of fibrosis deposition in space of Disse in different age groups.
Material and methods: Different ages of albino rats ( 6, 12, 18, 24, 30 and 36 months ) were chosen and sacrificed. Morphometric and serological parameters were assessed and the liver samples were processed for histological and immunohistochemical staining.
Results: Immunohistochemical staining revealed a gradual increase in TNC deposition from first to forth group then gradual decrease occurred. Masson's stain revealed gradual increase of fibrosis in space of Disse deposition from 2nd to 6th group.
Conclusion: TNC appear and increase before appearance of fibrosis but when fibrosis is formed TNC is down regulated again.