Ischemic versus cytotoxic damage in the white graft reaction. Its relationship to hyperacute kidney rejection.

"White" skin grafts on appropriately sensitized allografted mice are ischemic and necrotic. The ischemia occurs because of failure to form anastomoses between host and graft vessels. This failure is not due to altered host vascular function but correlated with obliterative (nonthrombotic, non-necrotizing) changes of graft vessels at the interface. It appears that the ischemia of white grafts, in contrast to that observed in hyperacutely rejected renal allografts, is not the cause of the necrosis, but vice versa. The necrosis of white grafts, which begins during the first 24 hr after their placement, is probably related to a very early immune assault on the graft as a whole. The nature and the pathways of this immune assault are not the subject of this study.