[The relationship between hypoxia inducible factor-1 alpha expression and novoendotheliasis after autogenous vein...

To elucidate the relationship between the level of hypoxia inducible factor-1alpha (HIF-1alpha) expression and novoendotheliasis after autogenous vein grafting.

40 Wistar rats underwent right internal jugular vein to common jugular artery interposition grafting. Twenty rats were killed 7 and 14 days after the grafting respectively and the grafted veins were harvested respectively. Twenty rats not undergoing grafting were used as controls. The expressions of HIF-1alpha mRNA and protein and vascular endothelial growth factor (VEGF) mRNA and protein were examined by using reverse transcription polymerase chain reaction, Western blotting, and immunohistochemistry. Electron microscope was used to observe the process of vascular novoendotheliasis.

The percentage of HIF-1alpha positive cells 7 days after grafting was 20.5 +/- 6.2%, significantly higher than that 14 days after (12.3 +/- 3.7, P < 0.01) and that of the controls (0.5 +/- 0.1%, P < 0.01). The percentage of HIF-1alpha positive cells 14 days after grafting was significantly higher than that of the controls too (P < 0.01). The expression of HIF-1alphamRNA 7 days after grafting was 53.2 +/- 9.3, significantly higher than that 14 days after grafting (43.2 +/- 6.3, P < 0.01) and that in the control (29.4 +/- 5.6, P < 0.01). The expression of HIF-1alpha7 mRNA 14 days after grafting was significantly higher than that of the controls too (P < 0.01). The expression of HIF-1alpha protein 7 days after grafting was 5.6 +/- 0.4, significantly higher than that 14 days after grafting (3.5 +/- 0.2, P < 0.01) and that in the control (0.8 +/- 0.1, P < 0.01). The expression of VEGF protein 7 days after grafting was 2.2 +/- 0.1, significantly higher than that of the control (0.5 +/- 0.1, P < 0.01). Novoendotheliasis was seen 7 days after grafting and decreased 14 days after. The expression of HIF-1alpha was positively correlated with the expression of VEGF (r = 0.903, P < 0.01).

HIF-1 alpha is closely related to novoendotheliasis. The deficiency of HIF-1 alpha expression plays an important role in intima hyperplasia.