Evaluation of initial hepatic allograft function with changes of free plasma amino acids in canine orthotopic liver transplantation

Abstract We investigated the correlation between amino acid level and hepatic graft function. Plasma amino acid levels were measured at three time periods during canine orthotopic liver transplantation. During the anhepatic phase, plasma amino acid levels rose except for tryptophan. Cystine and alanine (Ala) increased significantly to 210 ± 28% ( n = 20, mean ± SEM) and 203 ± 11% from preoperative values (100%), respectively. In animals successfully surviving without hepatic insufficiency after transplantation of fresh livers ( n = 7), plasma amino acid levels were restored to preoperative values within 3 hr following reperfusion. On the other hand, in animals that died from hepatic insufficiency within 5 days after grafting of warm ischemically damaged livers ( n = 8), plasma amino acids, especially Ala, phenylalanine, total free plasma amino acids, and aromatic amino acids progressively increased to 216 ± 25, 274 ± 36, 152 ± 15, and 152 ± 15% at 3 hr after reperfusion. These were significantly higher compared to those of the group of animals transplanted with fresh livers ( P n = 5), amino acid levels were at high values at 3 hr. These results suggest that in animals having good graft function, plasma amino acid levels are restored to preoperative values by 3 hr after reperfusion. In other cases, primary nonfunction should be strongly suspected after liver transplantation.