Immunohistochemical study of the ameliorative effect of Vitamin E on liver regeneration after different periods of partial hepatectomy

The liver is almost unique in its capacity for regeneration after hepatectomy but the exact mechanisms are not yet fully clarified. Antioxidants have been shown to promote liver regeneration after major hepatectomy. The present study evaluated the ameliorative effect of Vitamin E administration on the liver regeneration after different periods of partial hepatectomy (PH) in rats. Fifty-six adult male albino rats were divided into three groups: Control sham operated group; partially hepatectomized group which were divided into three subgroups sacrificed at 1day, 3 days and 7days after the operation respectively; Partially Hepatectomized group with Vitamin E pretreatment before PH where the rats were given a daily oral dose of Vitamin E until the time of sacrifice of the rats. Immunohistochemical detection of proliferating cell nuclear antigen (PCNA) and labeling index were demonstrated. After PH, the PCNA positive hepatocytes and the PCNA labeling indices were significantly high after the 1 day and then much decreased after the 3 day, to be followed by a slight increase at the 7 day. Vitamin E pretreatment in PH rats resulted in a decrease in PCNA positive cells and its labeling indices in the 1 day with a gradual increase in the 3 and 7 days. Vitamin E has an inhibitory effect in the first 24 hours on liver regeneration followed by stimulatory effect at the third and seventh days after PH. These data indicated that Vitamin E pretreatment has an important role in regulation and enhancement of liver regeneration after PH.