Objective: To analyze, during two different moments of liver regeneration, the effect of the immunosuppressant Tacrolimus on the 70% hepatectomy model-induced liver regeneration in adult rats.
Methods: Forty Wistar adult rats, weighing 510.08 + 11.66 g were randomly divided into two groups, each group divided into two subgroups according to the death day after 70% hepatectomy . According to the group of study, rats received 0.1 mg/kg/day of Tacrolimus or the same volume of saline solution, by gavage. After three days of pre-therapy, all animals were submitted to 70% hepatectomy by resection of median and left lateral hepatic lobes which were weighed for posterior calculation of liver regeneration by Kwon's formula. Twenty four hours or seven days after hepatectomy ten rats of each group were killed; the remaining liver (regenerated) was entirely resected, weighed and sampled for mitotic index on hematoxylin-eosin staining and immunohistochemical assays with PCNA and Ki-67 markers. Data were statistically analyzed by Mann-Whitney or Student "t" tests, with significance level of 5% (p<0.05).
Results: Rats receiving tacrolimus showed statistically significant higher levels of liver regeneration when compared to placebo according to Kwon's formula, mitotic index and PCNA marker. Identical trend was found with Ki-67 marker, but without statistical significance.
Conclusion: Tacrolimus-based immunossuppression has stimulatory effect on liver regeneration process induced by 70% hepatectomy in adult Wistar rats.