Objective:To study the effect of hydrocortisone (HC) on apoptosis and expression of apoptosis- associated proteins in the intestinal epithelium of fetal mice.Methods:The duodena and colons were taken from E13.5d and E14.5d fetal mice respectively

and cultured with different doses of HC (0 μg/ml

0.5μg/ml

1.0μg/ml

2.0μg/ml).After 24h

the samples were sliced up into the paraffin sections.Some sections were stained with HE to count the numbers of apoptotic bodies (NAB)in the fetal intestinal epithelium with stereological method.Others were stained with the immunohistochemical method to observe the expression of Bcl-2

Bax

P53 and c-Fos.Results:①In each experimental group

the NAB were higher than that of control group( P <0.05)

and there was a positive correlation between the doses of HC and the NAB( P <0.01).②In all experimental group

the expression of Bcl-2 in the intestinal epithelium of fetus was lower than that of control group( P <0.05)

and there was a negative correlation between the doses of HC and the expression of Bcl-2( P <0.01).But the expression of Bax and c-Fos in experimental group was higher than that of control group( P <0.05)

and there was a positive correlation between the doses of HC and the expression of these proteins( P <0.01).The significant change in expression of P53 was not observed.Conclusion:HC can increase the intestinal epithelium-apoptosis of fetal mice in vitro.The effect may be a P53-independent mechanism completeed through restraining the expression of Bcl-2 and promoting the expression of Bax and c-Fos.