(A–E) Protein from colonic extracts was separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by immunoblotting for Bax, Bcl-2, Bcl-xL, cytochrome c, p53 and phospho-p53. Bax, cytochrome c and phospho-p53 were markedly expressed in rats treated with TNBS alone. On the contrary, Bcl-2 and Bcl-xL were markedly reduced in rats treated with TNBS alone. However, glutamine administration partially abolished the changes in Bax, Bcl-2, Bcl-xL, cytochrome c and phospho-p53 expression induced by TNBS. Results are representative of four independent experiments. Equal loading of proteins is illustrated by β -actin bands. (A) Representative Western-blot photographs for Bax, Bcl-2, Bcl-xL, cytochrome c, p53, phospho-p53, and β-actin. (B) Densitometric quantification of ratio Bax/Bcl-2. (C) Densitometric quantification of Bcl-xL. (D) Densitometric quantification of cytochrome c. (E) Densitometric quantification of phospho-p53. Data are expressed as mean ± S.E.M. from 8 rats. *P<0.05 compared with control group. #P<0.05 compared with TNBS group. &P<0.05 compared with same group 2 d.