Changes in Serum Cytokine Concentration : A Morphological Study of Liver Cirrhosis Induced by Common Bile Duct Ligation in Rats

BACKGROUND Liver cirrhosis is a diffuse hepatic fibrosis, and nodule formation. The transforming growth factor-beta 1 (TGF-beta 1) and interleukin-10 (IL-10) are very important cytokines in hepatic fibrogenesis. The aim of this study was to examine the relationship between the changes of the serum cytokines and morphological changes following common bile duct ligation in experimental rats. METHODS Common bile ducts of fifty male Sprague-Dawley rats were ligated and seven male rats were set aside as controls. Five rats each were sacrificed in 1, 2, 4, 6, 8, and 10 experimental weeks. Light microscopic studies and liver function tests were performed during the above experimental weeks. The levels of serum TGF-beta 1 and IL-10 were analyzed by ELISA. Also, alpha smooth muscle actin (alpha-SMA) immunohistochemical stains were performed. RESULTS On the eighth week after common bile duct ligation, most hepatic lobular areas had been replaced by proliferated bile ducts and fibrous tissue (typical biliary cirrhosis). Serum TGF-beta 1 levels between the control group and the common bile duct ligation group showed statistically significant changes. The alpha-SMA was stained at proliferated bile ducts. These findings were correlated with each other. CONCLUSION Thus, this experiment may clarify our understanding of the mechanism in liver fibrogenesis. Also, indicated is a need to explore the therapeutic potential of these cytokines as anti-fibrotic agents.