Ultrastructural and immunohistochemical study of ITO cells of rat in carbon tetrachloride -induced liver fibrosis and the protective effect of vitamin A

ABSTRACT

The hepatic stellate cells, Ito cells, were known to play multiple roles in liver histopathology. This study was undertaken to explore the role of these cells in carbon tetrachloride [CCL4]- induced liver fibrosis, histologically and immunohistochemically, and to investigate the protective effect of vitamin A. Fifty rats were used and divided into three groups. The first group served as a control. The rats of the second group were injected twice a week with CCL4 for eight weeks, while the animals of the third group were pretreated with Vitamin A before injection of CCL4. At the end of each experiment, specimens from the liver of the animals were taken and processed for transmission EM study and immunohistochemical demonstration of GGaI fibrillary acidic protein [GFAP] and alpha smooth muscle actin [alphaSMA]. Eight weeks after CCL4 administration, thick and irregular C.T. septa with formation of definite lobules and pseudolobules were detected. GFAP-positive to cells were few in number intralobularly and in the C. T. septa. In contrast, there were numerous alphaSMA-positive cells. However, in Vitamin A-pretreated rats numerous GFAP-positive ito cells and few alphaSMA-positive cells were detected in-side the lobules. Ultrastructurally, three types of Ito cells were detected in the liver of CCL4-intoxicated rats. Some Ito cells resembled myofibroblasts, others contained many lipid droplets and activated rER, while septal Ito cells attained a fibroblast like feature. On the contrary, in Vitamin A pretreated group, Ito cells contained numerous lipid droplets and had few dilated rER cisternae. From this current study, we that immunohistochemical demonstration of GFAP and alphaSMA may be alpha method for studying hepatic fibrogenesis. Moreover, it is recommended that, Vitamin A may have a protective effect against carbon tetrachloride-induced hepatotoxicity