Morphological changes in 49 chacma baboons after cardiac allografts.

The morhpological changes in 49 chacma baboons after cardiac transplantation were studied by light and electron microscopy. Non-immunosuppressed grafts were tolerated for an average of 10 days and immunosuppressed grafts for 18 days. Serial biopsy specimens of non-immunosuppressed grafts showed a progression in severity of rejection changes. Electron microscopy mirrored the light microscopic changes. Rejection changes in the baboon appear similar to those encountered in human and canine allografts. Heterotopic transplants showed more severe grades of rejection than would be compatible with life in orthotopic transplants.