ABSTRACT
A new model of limb xenotransplantation has been developed to determine whether the
newer immunosuppressive agents, FK-506 and RS-61443, either alone or in combination,
can delay the rejection of a composite limb xenograft from donor Golden Syrian hamsters
to recipient Lewis rats. Using a short-term course of immunosuppression for 14 days
post-transplant, both FK-506 2 mg/kg/day and RS-61443 30 mg/kg/day were able to delay
rejection. FK-506-treated animals had a mean rejection time of 10.2 days and RS-61443-treated
animals had a mean rejection time of 10 days, compared with a mean rejection time
of 6.4 days in non-immunosuppressed controls. Combination and sequential immunosuppression
with both FK-506 and RS-61443 did not produce any improvement, compared with single-agent
immunosuppression, and were quite toxic. Histologically, FK-506 seemed to prevent
signs of rejection in the skin and muscle components of the limb xenograft better
than RS-61443.
