VASCULAR ENDOTHELIAL GROWTH-FACTOR (VEGF) EXPRESSION DURING ARTERIAL REPAIR IN THE PIG

Objectives: Vascular endothelial growth factor (VEGF) is reported to b e a potent and specific mitogen for endothelial cells (EC) and an indu cer of angiogenesis in vivo. Originally called vascular permeability f actor (VPF), VEGF also increases permeability of microvessels to circu lating macromolecules. The aim of this study was to examine whether th e 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-endo thelialised using an inflated balloon catheter. At a number of time-po ints after injury these arteries were harvested together with uninjure d contralateral arteries. Sections of arteries were used for RNA analy sis by Northern blots and for protein localisation studies by immunohi stochemistry. Results: Two VEGF transcripts (2.0 kb, 4.5 kb) were mark edly elevated in pig artel-ies soon after injury. Newly synthesised VE GF protein was located in smooth muscle cells (SMC) throughout the med ia of injured arteries. Conclusions: The elevated expression of VEGF b y SMC in denuded porcine arteries is evidence that this cytokine plays a role in the injury response of large arteries. Since several biolog ical activities have been identified for VEGF, the function of this cy tokine in the arterial repair process remains to be determined.