[Action of cyclosporin A and cytimun on the survival time of accessory heart transplants (author's transl)].

The new immunosuppressive substances Cyclosporin A (group A = 15 mg) and Cytimun = ASTA 5122 (group B = 15 mg, group C = 5 mg) were tested in rats that received accessory cervical heart transplants. A syngeneic (DA leads to DA) and a strongly allogeneic (PVG leads to DA) strain combination served as controls of operative and immunogenetic parameters. Whereas Cyclosporin A (group A) brought about a local transplant tolerance in 90% of cases, at a dosage of 15 mg/kg per day (group B), Cytimun led in 88% of cases to lethal intoxication of the recipients. At a dosage of 5 mg/kg per day (group C), 67% of the animals survived; however, they showed electrocardiographic evidence of possible temporary rejection crises between the 5th and the 13th day.