Effect of lacking intestinal bile acid on liver regeneration in rats

Objective To investigate the effect of the lack of intestinal bile on liver regeneration after hepatectomy.Methods The model of interference with intestinal bile acid metabolism in rats was established by feeding rats with 0.2% cholic acid（cholic acid loading group）, 2% cholestyramine resin（lack of bile group）and feeding the standard diet as the control group.Liver regeneration was compared among the 3 groups at 0, 1, 2, 3, and 7 d after 70% partial hepatectomy（PH）in rats and mRNA expression of the rate-limiting enzyme of bile acid biosynthesis（CYP7a1）and farnesoid X receptor （FXR）were detected.Results The rate of liver regeneration was significantly lower on days 3 and 7after PH in the lack of bile group than in the other groups（P〈0.05）.On day 1, the labeling indices of PCNA and Ki-67 in the lack of bile group（22.21% ±2.31%、 17.25 % ± 6.50 %）were lower than those in the cholic acid loading group（44.4%±4.92%、 30.83% ± 3.91%）and control group （38.74% ±6.42% 、27.04% ±7.22%）and the peaking of labeling indices was delayed.After PH, the mRNA expression of FXR was significantly lower in the lack of bile group than in other groups.However, CYP7al mRNA had a trend towards increase after PH and was higher than that in other groups.Conclusion Lack of intestinal bile results in delayed liver regeneration of normal rat liver accompanied by decreased expression of FXR mRNA after hepatectomy. Key words: Liver regeneration;  Bile acid;  Farnesoid X receptor