Hepatic protein synthesis rate of liver specimens as a predictor of viability in rat cold ischemia liver transplantation model

Background/Aims: We have previously reported that the hepatic protein synthesis rate, calculated as the uptake rate of L-[4.5 ³H] leucine by the fraction during a 10-min incubation of a 16-G needle biopsy specimen of liver tissue, represents a high level of liver function and is therefore useful for evaluating liver function. We investigated the hepatic protein synthesis rate level in a pretransplant liver to learn if it might predict the outcome in a rat orthotopic liver transplantation model. Methods: Grafts were stored, liver specimens were obtained using a 21-G Chiba type II skinny needle, and the hepatic protein synthesis rate was calculated. Subsequently, liver transplantation was performed, and the hepatic protein synthesis rate revascularized liver, tissue blood flow rate, serum alanine amino- transferase, lactate dehydrogenase, hyaluronic acid, ketone body rate, and 2- week survival were examined. Results: The hepatic protein synthesis rate of pre-transplant liver was correlated with parameters of post-transplant liver function: hepatic protein synthesis rate of the revascularized liver (r=0.92, p<0.0001), tissue blood flow rate (r=0.77, p<0.004), serum alanine aminotransferase (r=-0.69, p<0.003), lactate dehydrogenase (r=-0.54, p<0.03), hyaluronic acid (r=-0.86, p<0.0002), and ketone body rate (r=0.57, p<0.02). Pretransplant hepatic protein synthesis rate in survivors was 263.6 ± 54.2 nmol/mg protein/10 min, while that in nonsurvivors was significantly lower at 162.0 ± 39.0 (p<0.0001). When evaluation was made using a logistic regression model, the accuracy predicted using the value of hepatic protein synthesis rate was 95% (19/20). Conclusions: These results suggest that measuring the hepatic protein synthesis rate of the grafts with a 21-G Chiba type II skinny needle may be a predictive criterion in the assessment of graft viability.