Objective: To evaluate the effects of recombinant human thrombopoietin (rhTPO) on platelet count (PLT) and liver function in acute liver failure (ALF) rats by observing the dynamic changes of PLT, thrombopoietin (TPO) and liver function during ALF.
Methods: Twenty-four male Sprague-Dawley (SD) rats were divided into model group, TPO group and interleukin-11 (IL-11) group using a random number table method, with eight rats in each group. All rats were intraperitoneally injected with D-galactosamine (D-GalN, 1 500 mg/kg, dosed within 72 hours) to induce the ALF model. After modeling, rats in TPO group was received subcutaneous injection of 15 μg/kg of rhTPO for 5 days, and rats in IL-11 group was received subcutaneous injection of 0.45 mg/kg of IL-11 for 5 days. Venous blood samples were collected before and at 1, 3, 5, 7 and 12 days after molding for whole blood cell detection. The level of TPO in serum was detected by enzyme-linked immunosorbent assay (ELISA). Liver function indexes including serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBil) and albumin (ALB) were measured before and at 1, 3 and 5 days after modeling. The rats were sacrificed 12 days after the modeling, and the pathological changes of liver tissue were observed by hematoxylin-eosin (HE) staining.
Results: Two rats in each group died within 24-48 hours after modeling. HE staining showed that all three groups of ALF rats showed large flake necrosis of hepatocytes, disorder of hepatic lobular structure, mesh scaffold collapse, hepatic sinus congestion and hemorrhage, and flake infiltration of inflammatory cells on day 12 after modeling. The levels of serum ALT, AST and TBil of rats in each group were significantly increased 1 day after modeling and then decreased. The level of ALB decreased significantly on the first day after modeling and then increased, but there was no significant difference in the trend of liver function indexes among the three groups. PLT in the three groups decreased rapidly on day 1 after modeling, and then recovered gradually with the improvement of liver function. The PLT of the TPO group rose to the peak value 7 days after molding and was significantly higher than that of the model group [PLT (×109/L): 1 673.3±347.5 vs. 855.3±447.0, P < 0.05], while there was no significant difference between the IL-11 group and the model group [PLT (×109/L): 1 350.3±386.6 vs. 855.3±447.0, P > 0.05]. The level of serum TPO of the three groups increased significantly on day 1 after modeling, then decreased, and dropped to the lowest value on day 5, but there was no significant difference in the trend of serum TPO level among the three groups.
Conclusions: PLT in ALF rats decreased rapidly in the early stage and recovered gradually with the improvement of liver function, and the serum TPO level increased first and then decreased. Injection of rhTPO can significantly increase PLT in ALF rats, but has no significant effect on liver function and survival rate.