Studies on competitive inflammatory sites. I. Influence of the size of sensitizing skin implants on second-set corneal graft reactions.

A dependence of second-set corneal graft reactions on the size of the sensitizing skin allografts was established in different rat donor-recipient pairs, each of which involved a response to the B2 major histocompatibility antigen. Sensitizing skin sizes larger or smaller than the optimal size were found to result in less intense reaction in subsequently placed second-set corneal allografts. The data obtained support the view that a persisting skin allograft not only sensitizes, but constitutes a competitive inflammatory site. The latter role of a first-set skin allograft may be facilitated by being both more accessible to inflammatory cells and larger than corneal grafts. The relative strength of the sensitizing and competitive effects of a first-set skin allograft apparently influences the fate of a second-set corneal allograft.