Objectives: To investigate the relationship between the apoptosis of sinusoidal endothelial cells (SEC) and the hepatocyte injury of the livers after their transplantation into rats.
Methods: Male SD rats were divided into three groups randomly: sham group, UW1h group and UW12 h group. Orthotopic liver transplantations were performed using the technique described by Kamada with a modification. A survival rate curve was made using the Kaplan-Meier method. Liver tissue specimens and blood samples were collected at different time points after the surgeries. Six animals were sacrificed at each time-point. The liver injury was evaluated by serum ALT and HA levels. The incidence of apoptosis in SECs was measured using the Tunel method. Additionally, the typical morphology indication of apoptosis was observed by transmission electron microscopy.
Results: The survival rate at 168 h in the UW12 h group was significantly lower than that in the UW1h group (F = 6.39, P<0.05). The levels of serum ALT and HA were significantly higher in UW12 h group than those in UW1h group (F = 3.99, P<0.05; F = 12.43, P<0.05). The serum ALT level reached its peak at 6 h after transplantation in both groups. The AI of SEC was significantly higher in the UW12 h group than those in the UW1h group and sham group (F = 63.58, P<0.01; F = 86.58, P<0.01). The apoptosis index (AI) in the UW1h group and in the UW12 h group both reached their peak at 6 h postoperatively and the AI of SEC of each group was positively correlated with their serum ALT levels significantly (r = 1.0, P,0.01; r = 0.962, P<0.05).
Conclusion: The increase of apoptosis of SEC is significantly correlated with the dysfunction of the livers after transplantation in rats, and the dysfunction was mainly caused by the process of cold preservation/reperfusion injury.