Platelets in hyperacute rejection of heterotopic cardiac allografts in presensitized dogs. An experimental study

Experiments were carried out to determine whether platelet aggregation plays a primary role in cardiac allograft hyperacute rejection, as has been observed in renal allograft hyperacute rejection. Dogs were presensitized by multiple skin grafts before a cervical heterotopic cardiac allograft was placed. One group of dogs was treated with sulfinpyrazone, a platelet inhibitor, and another was not. In the majority of the untreated dogs, the cardiac transplants were rejected hyperacutely and showed, morphologically, platelet aggregation followed by vascular disruption. In the treated dogs, hyperacute rejection was prevented, but the cardiac transplants were later rejected by primary cellular rejection. These data and the results from the experiments of other researchers lead us to propose that platelets are the "effector" of hyperacute rejection.

Platelets in early hyperacute allograft rejection in kidneys and their modification by sulfinpyrazone (Anturan) therapy. An experimental study

Experiments were carried out on mongrel dogs to study the early ultrastructural changes in hyperacute rejection of kidney. Renal allografts were performed on dogs presensitized by three to five skin grafts. The animals were grouped in pairs, control and treated with sulfinpyrazone, a platelet inhibitor. The electron microscopic studies showed that the earliest change in the kidney was aggregation of platelets mainly in the peritubular capillaries and a few glomeruli. Later, platelets showed degranulation with vascular damage leading to rejection of kidney. Treated dogs showed less tendency for platelets to aggregate, and graft survival was prolonged. The role or platelets in the hyperacute rejection is discussed.

Lipid accumulation in renal arterioles due to platelet aggregate embolism

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