Expression of vascular endothelial growth factor and basic fibroblast growth factor in acute rejection reaction following rat orthotopic liver transplantation

The aim of the present study was to investigate the expression levels of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in acute rejection reaction (ARR) following orthotopic liver transplantation in a rat model. Serum VEGF and bFGF levels were detected using ELISA, and their expression levels in liver and spleen tissues were determined using immunohistochemistry. The mRNA expression levels of VEGF and bFGF were detected by conducting a quantitative polymerase chain reaction during the ARR following orthotopic liver transplantation. The expression levels of VEGF and bFGF in the serum 3 days following liver transplantation were significantly higher compared with those in the other groups (1 and 7 days following transplantation; P<0.01). In addition, the numbers of cells in the liver tissue that were shown to be positive for the expression VEGF and bFGF using immunohistochemistry were significantly higher 3 days following transplantation than at the other time points (P<0.0001). Furthermore, the numbers of cells positive for VEGF and bFGF expression in the spleen detected 3 days following the transplantation surgery were also significantly higher compared with those at the other time points (P<0.01). VEGF and bFGF mRNA expression levels were also increased from 1 day following the surgery and reached a peak at day 3, prior to declining gradually and remaining at a relatively high level. VEGF and bFGF mRNA expression levels changed dynamically, by peaking and then declining, in ARR following orthotopic liver transplantation. These changes may have an important impact on angiogenesis and the inflammatory reaction, and the identification of these changes increases the current understanding of ARR following orthotopic liver transplantation.