Cellular survival in rat vein-to-artery grafts - Extensive depletion of donor cells

Microsurgical models of vein-to-artery graft surgery have been developed in rats as a means of assessing vein graft adaptation and neo-intimal hyperpl asia. Neo-intimal hyperplasia in these grafts is often attributed, at least in part, to an adaptive response by venous smooth muscle cells to the incr eased intraluminal pressure of the arterial pressure. However, considerable evidence suggests complete or near-complete cellular replacement in these grafts. A series of experiments were undertaken in which male vein or arter y grafts were placed into either allogeneic female nude rat hosts or into s yngeneic WKy female hosts as a means of determining donor cell survival. Gr afts were removed at postsurgery week 2 or week 6 and the fate of the donor male cells assessed by PCR amplification of the testis-determining gene Sr y. The SU gene was undetectable in 2-week male to female vein grafts. When left for 6 weeks, donor cells were detectable in vein grafts only after mul tiple 50-cycle PCR analyses. Minimal donor cell survival was not due to an allograft response, as donor male cells were readily detectable in WKy male to female nude rat artery-to-artery grafts. These data were not nude rat s pecific, as poor donor cell survival was also evidenced in syngeneic male t o female vein-to-artery grafts. In conclusion, we demonstrate only marginal survival of donor cells in rat vein-to-artery grafts. Neointimal hyperplas ia in these grafts was not a consequence of donor venous smooth muscle cell proliferation.