Heart transplantation in endotoxin shock.

The condition of the heart from dogs in endotoxin shock was evaluated, and all dogs in the control group receiving 5 milligrams per kilogram to Eschericia coli endotoxin died within two to 14 hours. Hearts from four other dogs receiving the same dosage of endotoxin were allografted orthotopically into healthy recipient dogs. The donor heart was taken in the terminal phase of shock, after the blood pressure of the donor had declined to 50 millimeters of mercury or less. All four heart allografts functioned normally in the healthy hosts, demonstrating that lethal levels of gram-negative endotoxin do not produce direct irreversible damage to the myocardium or to the conduction mechanism of the heart. This also was shown in one pair of monkeys; the donor monkey had received ten times the dosage of endotoxin used in the dogs. This heart transplant model offers considerable advantage in functional studies of the heart after irreversible shock.