Expression pattern and action analysis of genes associated with the responses to chemical stimuli during rat liver regeneration

AIM： To study the genes associated with the responses to chemokines, nutrients, inorganic substances, organic substances and xenobiotics after rat partial hepatectomy （PH） at transcriptional level. METHODS： The associated genes involved in the five kinds of responses were obtained from database and literature, and the gene expression changes during liver regeneration in rats were checked by the Rat Genome 230 2.0 array. RESULTS： It was found that 60, 10, 9, 6, 26 genes respectively participating in the above five kinds of responses were associated with liver regeneration. The numbers of initially and totally expressed genes occurring in the initial phase of liver regeneration （0.5-4 h after PH）, G0/G1 transition （4-6 h after PH）, cell proliferation （6-66 h after PH）, cell differentiation and structurefunctional reconstruction （66-168 h after PH） were 51, 19, 52, 6 and 51, 43, 98, 68 respectively, illustrating that the associated genes were mainly triggered in the initiation and transition stages, and functioned at different phases. According to their expression similarity, these genes were classified into 5 groups： only upregulated （47）, predominantly up-regulated （18）, only down-regulated （24）, predominantly down-regulated （10）, and up- and down-regulated （8）. The total times of their up-regulated and down-regulated expression were 441 and 221, demonstrating that the number of upregulated genes is more than that of the down-regulated genes. Their time relevance and gene expression patterns were classified into 14 and 26 groups, showing that the cell physiological and biochemical activities were staggered, diversified and complicated during liver regeneration in rats. CONCLUSION： The chemotaxis was enhanced mainly in the forepart and metaphase of LR. The response of regenerating liver to nutrients and chemical substances was increased, whereas that to xenobiotics was not strong, One hundred and seven genes associated with LR play important roles in the responses to chemical substances.