ABSTRACT
OBJECTIVE: To detect the expression of proliferating cell nuclear antigen (PCNA) in severely damaged intestinal mucosa due to high-dose 5-FU exposure. METHODS: Thirty-two adult C57BL/6J mice were subjected to daily intraperitoneal high-dose 5-FU injection at 150 mg/kg for 5 consecutive days, and on days 1, 3, and 5, the mice were sacrificed to obtain the small intestinal tissue for HE straining and immunohistochemistry for detecting PCNA expression. Another 8 mice with intraperitoneal PBS injection served as the control group. RESULTS: High-dose 5-FU exposure of the mice resulted in severe intestinal mucous damage, with complete destruction of the villi and crypts and significantly increased cells positive for PCNA expression (P<0.01). CONCLUSION: High-dose 5-FU treatment can significantly increase the PCNA index, and the cells expressing PCNA can be closely associated with regeneration of the severely damaged mucosa due to the exposure.