Abstract: The aim was to study the effect of portal hypertension (PHT) on tumor necrosis factor (TNF-α) in venous plasma, the influence of splenectomy and splenic artery ligation on TNF-α levels in venous plasma in model rats and to investigate the relation between TNF-α and NOS levels in venous plasma in PHT rats. Healthy Wistar rats were randomized into four groups: The latter three groups were used to established PHT model. TNF-α levels in venous plasma were dynamically measured by radioimmunoassay (RIA) at points after the splenectomy and SAL; NOS levels in venous plasma were determined 14 d after operation. The mortality between SLC group and SAL group were compared 4 weeks after operation. Light microscope were applied to observe the pathological change. PHT TNF-αlevels in venous plasma were significantly higher than NCG group (P<0.01). SLC group TNF-αin plasma increased significantly, compared with MCG group(P<0.01), at points (3 d, 7 d, and 14 d) after splenectomy. SAL group TNF-α levels in venous plasma were slightly higher than MCG group (P> 0.05), and were significantly lower than SLC group (P< 0.01) at points (3 d, 7 d, 14 d) after SAL. MCG group NOS levels in venous plasma were significantly elevated(P<0.01), compared with NCG group, there was a positive correlation(r=0.946, P<0.01) between TNF-α levels and NOS levels in venous plasma, while SAL group NOS levels were significantly reduced (P< 0.01), compared with MCG group and SLC group respectively. The morbidity in SLC group was remarkably higher than that of SAL group (P< 0.05). In PHT, TNF-α levels in venous plasma significantly increase, possibly play an important role in the course of PHT. TNF-αlevels in venous plasma significantly increase after splenectomy, while the morbidity also elevate remarkably. Compared with PHT model rats, SAL group TNF-α levels and the morbidity don't increas significantly, and prognosis can be improved.

Key words: cirrhotic portal hypertension, tumor necrosis factor, splenectomy, splenic artery ligation