Fetal gastric and colonic implants in syngeneic and allogeneic mice developing typical inflammatory changes.

Implants of fetal stomach and colon under the kidney capsule of syngeneic, and H-2 compatible and H-2 incompatible allogeneic mice were examined histologically at different time intervals after the procedure. According to the time of implantation typical inflammatory changes were seen in syngeneic stomach and colon implants, which resembled changes seen in chronic atrophic gastritis and chronic ulcerative colitis. Immunofluorescence studies showed that the host developed antibodies against fetal antigens, while there was no evidence for cellular immune response to fetal syngeneic antigens with the direct leukocyte migration inhibition test. Possible explanations for these results are discussed.