Vascular endothelial growth factor (VEGF) expression during arterial repair in the pig

Objectives: Vascular endothelial growth factor (VEGF) is reported to be a potent and specific mitogen for endothelial cells (EC) and an inducer of angiogenesis in vivo. Originally called vascular permeability factor (VPF), VEGF also increases permeability of microvessels to circulating macromolecules. The aim of this study was to examine whether the VEGF gene was expressed in porcine arteries following denudation of EC. Design: Experimental animal model with mechanical injury to large arteries. Methods: The right iliac artery of juvenile pigs was de-endothelialised using an inflated balloon catheter. At a number of time-points after injury these arteries were harvested together with uninjured contralateral arteries. Sections of arteries were used for RNA analysis by Northern blots and for protein localisation studies by immunohistochemistry. Results: Two VEGF transcripts (2.0 kb, 4.5 kb) were markedly elevated in pig artel-ies soon after injury. Newly synthesised VEGF protein was located in smooth muscle cells (SMC) throughout the media of injured arteries. Conclusions: The elevated expression of VEGF by SMC in denuded porcine arteries is evidence that this cytokine plays a role in the injury response of large arteries. Since several biological activities have been identified for VEGF, the function of this cytokine in the arterial repair process remains to be determined.