The Relation Of TGF-β₁ Expression And Epithelial Cell Apoptosis On Rat Enteral Mucosae In Cold Stress

Objectives: To investigate the relation of transforming growth factor β₁(TGF- β₁) expression on rat enteral mucosae and enteral epithelium mucosaecell apoptosis in cold stress.Materials and Methods: 60 SD male rats, weight 180g to 220g, 80 to 100days old (supplied by West China Medical Center animal institute).Randomization: NC control group, CS test group, DCS medical interventiongroup ( Decorin inhibiting the activation of TGF- β₁). 20 rats per group. CSgroup and DCS group are exposed in cold stress, then after 2,4,8,10,12 and24 hours.7cm rat terminal ileums are excised and made into specimens, whilein NC group the terminal ileums are excised directly. These specimens arefixed by 10% neutral formalin, imbedded by paraffin, and sectioned. Measurethe expression of TGF- β₁ with immunohistochemistry,and apoptosis withDNA in situ end labeling(TUNEL) and DNA agarose gel electrophoresis.Results:1. Comparison of test group (CS group n=20) with normal control group (NCgroup n=20)l.lThe positive rate (59.09%and54.16%) of transforming growth factor- β₁expression at 8h and 12h in test group(CS group) is apparently higher thanthat in control group (16.67% )P<0.05 Above results indicate that the positiverate of transforming growth factor- P i expression on the rat enteral mucosaerise in cold stress.1.2 The apoptotic rate AI ( %) ( 25.69 ±8.09 andl9.65 ± 6. 61) of rat enteralepithelium mucosae cell at 8h and 12h in test group is apparently higher thanthat in control group AI (%) (4.41 ±1.87) P<0.05.Above results indicate that the apoptotic rate (AI) of rat enteral epitheliummucosae rise, and transforming growth factor & i(TGF- 0 i) maybe one of theinducing factors of rat enteral epithelium mucosae apoptosis (AT) in coldstress.2. Comparison of drug intervention group (DCS group n=20) with normal control group (NC group n=20)2.1 The positive rate of transforming growth factor- fl i expression in drug intervention group(DCS group) have no significant difference with that in normal control group.2.2 The apoptotic rate AI of rat enteral epithelium mucosae in DCS group have no significant difference with that in NC group.It indicates that Decorin can inhibit expression of TGF- P i on the rat enteral mucosae, which may result in inhibition of rat enteral epithelium mucosae apoptosis.3. Correlation analysis of test group , drug intervention group and normal control group.The positive rate of transforming growth factor- 0 i expression on rat enteral epithelium mucosae is positive correlation with the apoptotic rate AI of rat enteral epithelium mucosae (r=0.980> P<0.05) . It indicates that TGF- P i may be one of the important inducing factors of enteral epitheliummucosae apoptosis.Conclusion:There is significant apoptosis of rat enteral epithelium mucosae in cold stress.TGF- 0 i may be one of the important inducing factors of enteral epitheliummucosae apoptosis.