Long-term survival of heart and liver xenografts with splenectomy and FK 506.

We have reported that while hamster-to-rat liver xenograft survival is prolonged by FK 506, hamster hearts undergo humoral rejection under this immunosuppressant. Because the spleen has been shown to be one of the main sources of xenoantibodies,, and in vivo experiments have demonstrated that splenectomy (Spx) is able to increase the efficacy of various immunosuppressive agents after xenotransplantation,– we combined Spx with FK 506 to test whether survival of the intractable cardiac xenografts is prolonged, and of liver xenografts improved.