Influence of cyclophosphamide on homograft rejection.

Earlier work 1 has shown that cyclophosphamide (Cytoxan) significantly prolongs survival of skin homografts in rabbits. This appears to be a direct and specific effect of the drug upon the immune mechanism and not a nonspecific inhibition arising from a toxic state of the animals. The following is a report of a histological study of skin homografts exchanged between dissimilar strains of rabbits, comparing the rejection response between animals receiving cyclophosphamide and those which received no drug Methods and Material Standard, measured patches of full-thickness skin on the ears were exchanged between California and New Zealand strains of adult male rabbits weighing 2 to 3 kg. Two patches, each 3/4 inch square, were exchanged between each pair of rabbits, so that each rabbit bore two patches of homograft skin from his opposite strain partner on the dorsum of his left ear. Group 1 (control) animals received no drug. Group 2