Atherosclerosis in Normal and Von Willebrand PIGS: Cross-Aortic Transplantation Studies

Pigs with homozygous severe von Willebrand’s (vW) disease appear resistant to atherosclerosis. Normal and vW pigs matched by breed and weight received a high (2%) cholesterol diet from age 3 to 9 months and then the aortas were analyzed. Experiment 1, Auto-Aortic Transplantation: in 2 normal pigs a 7 cm aortic segment proximal to the aortic bifurcation was resected, the segments were reimplanted again and the diet started both auto-transplanted segments developed atherosclerosis. Experiment 2, Cross-Aortic Transplantation: the aortic segments of 5 normal pigs were cross-transplanted with the aortic segments of 5 other normal pigs. From the 10 cross-transplanted segments, 9 developed atherosclerbsis. Similar cross-transplantation between 2 vW pigs revealed no atherosclerosis in the transplanted segment in 1 pig (the other pig died at operation). Experiment 3, Exchange Cross-Aortic Transplantation: The aortic segments of 2 normal and 2 vW pigs were exchanged. The vW aortic segments in the recipient normal pigs revealed atherosclerosis and endothelial cell vW factor (present in the capillary endothelium of the aortic segment), while the normal aortic segments in the vW pigs did not reveal atherosclerosis or endothelial cell vW factor.

These preliminary findings further support the relationship between the Willebrand defect and the protection from atherosclerosis.