Expression of TNF-α and VEGF in the esophagus of portal hypertensive rats

摘要

AIM: To investigate the expression of tumor necrosis factor-alpha (TNF-α) and vascular endothelial growth factor (VEGF) in the development of esophageal varices in portal hypertensive rats. METHODS: Thirty male Sprague-Dawley (SD) rats in the model group in which a two-stage ligation of portal vein plus ligation of the left adrenal vein was performed, were divided into three subgroups (M_7, M_(14), and M_(21)) in which the rats were kiued on the seventh day, the 14th d and the 21 d after the complete portal ligation. Thirty male SD rats, which underwent the sham operation in the control group, were also separated into three subgroups (C_7, C_(14) and C_(21)) corresponding to the models. The expression of TNF-α and VEGF in the esophagus of all the six subgroups of rats were measured with immunohistochemical SP technique. RESULTS: The portal pressure in the three model subgroups was significantly higher than that in the corresponding control subgroups (23,82±1.83 vs 11.61±0.86 cmH_2O, 20.90±3.27 vs 11.43±1.55 cmH_2O and 20.68±2.27 vs 11.87±0.79 cmH_2O respectively, P < 0.01), as well as the number (9.3±1.6 vs 5.1±0.8, 11.1±0.8 vs 5.4±1.3 and 11.7±1.5 vs 5.2±1.1 respectively, P < 0.01) and the total vascular area (78 972.6±3 527.8 vs 12 993.5±4 994.8 μm~2, 107 207.5±4 6461.4 vs 11 862.6±5 423.2 μm~2 and 110 241.4±49 262.2 vs 11 973.7±3 968.5 μm~2 respectively, P < 0.01) of submucosal veins in esophagus. Compared to the corresponding controls, the expression of TNF-α and VEGF in M_(21) was significantly higher (2.23±0.30 vs 1.13±0.28 and 1.65±0.38 vs 0.56±0.30 for TNF-α and VEGF respectively, P < 0.01), whereas there was no difference in M_7(1.14±0.38 vs 1.06±0.27 and 0.67±0.35 vs 0.50±0.24 for TNF-α and VEGF respectively, P > 0.05) and M_(14) (1.20±0.25 vs 1,04±0.26 and 0.65±0.18 KS 0.53±0.25 for TNF-α and VEGF respectively, P > 0.05). And the expression of TNF-α and VEGF in M_(21) was significantly higher than that in M_7 (2.23?0.30 vs 1.14±0.38 and 1.65±0.38 vs 0.67±0.35 for TNF-α and VEGF respectively, P < 0.01) and M_(14) (2.23±0.30 vs 1.20±0.25 and 1.65±0.38 vs 0.65±0.18 for TNF-α and VEGF respectively, P < 0.01), but there was no difference between M_7 and M_(14) (1.14±0.38 vs 1.20±0.25 and 0.67±0.35 vs 0.65±0.18 for TNF-α and VEGF respectively, P > 0.05). CONCLUSION: In the development of esophageal varices in portal hypertensive rats, increased TNF-α and VEGF may be not an early event, and probably play a role in weakening the esophageal wall and the rupture of esophageal varices.