No reinnervation of hepatic sympathetic nerves after liver transplantation in human subjects.

Transplantation of the liver results in surgical denervation of the organ. However, it is not known whether and to what extent sympathetic reinnervation occurs postoperatively in the transplanted human liver. Thirty-two liver biopsies (right lobe) were obtained from 13 liver-transplanted patients 1, 3, 6, 12 or 30 months after transplantation and 11 biopsies were obtained from 11 non-transplanted subjects with normal liver tests. The concentrations of the sympathetic neurotransmitter norepinephrine and of epinephrine were determined in liver tissue homogenates. The concentration of norepinephrine was 0.019 +/- 0.05 nmol. g wet liver tissue-1 (mean and SE, n = 32) in the transplanted patients, which was only 1% of the concentration in biopsies from control subjects (2.180 +/- 0.420 nmol.g wet liver tissue-1). The hepatic norepinephrine concentration did not increase significantly over time in liver-transplanted patients during the observation period (0.015 +/- 0.008 nmol.g wet wt-1 (1 month post) (n = 8) vs. 0.024 +/- 0.018 nmol.g wet wt-1 (12 months post) (n = 6) and 0.012 +/- 0.006 nmol.g wet wt-1 (30 months post) (n = 5)) (p < 0.05). The liver tissue concentration of epinephrine was markedly lower in liver-transplanted subjects (0.01 +/- 0.003 nmol.g wet tissue-1) than in control subjects (0.04 +/- 0.007 nmol.g-1) (p < 0.01). This study indicates that within the first years after transplantation, there is no evidence of sympathetic liver nerve reinnervation in liver-transplanted patients.