Changes in T-lymphocyte subpopulations and serum lymphokine concentrations after partial hepatectomy in rats

The relationship between liver regeneration and immunological response does exist. Extrathymic T cells and serum lymphokines are believed to be changed after partial hepatectomy, but there is still much controversy. This study evaluates the changes of peripheral blood T-lymphocyte subpopulations, natural killer (NK) cells, serum lymphokines, and NK cells in the remnant liver after partial hepatectomy. Male Wistar rats weighing around 200 g were used as subjects. Partial hepatectomies (67%) were done. Counting T-lymphocyte subpopulations (includes T3, T4, T8, T-IL2R, and NK cells) by using fluorescin isothiocyanate or phycoerythrin was performed preoperatively and on 1,2,3,5,7, and 10 d postoperatively. Serum gamma-interferon (gamma-IFN), interleukin-2 and interleukin-2 receptor concentrations were measured. Absolute number of NK cells in the remnant liver was also counted. Rats with right-side nephrectomy, sham operation, and no operation were used as control groups. Comparing the difference between all groups, we found that all T-lymphocyte subpopulations in peripheral blood, serum gamma-IFN, peripheral blood NK cells, and the absolute number of NK cells in the remnant liver of hepatectomized rats increased markedly, and were significantly higher than control groups rats, on the fifth and seventh post-hepatectomy day. It is suggested that gamma-IFN and NK cells were activated markedly and might play important roles in the regulation of liver regeneration after partial hepatectomy.