Fk506 Inhibit Liver Regeneration in HOC Model Rat

Studies have shown that lymphocytes support hepatic oval cell (HOC)-dependent liver regeneration and FK506（Tacrolimus） is known as an immunosuppressor. Therefore, we studied the role of FK506 in HOC activation and/or proliferation to guide the clinical use of FK506.

Thirty male Lewis rats were randomly divided into 4 groups: (A) intervene in activation (n = 8), (B) intervene in proliferation (n = 8), (C) control HOC model (n = 8), and (D) pure partial hepatectomy (PH) (n = 6). The HOC model was established by 2AAF(2-acetylaminofluorene)/PH in groups A to C. FK506 (at a dose of 1 mg/kg/d) was given subcutaneously in group A except on operation day, and not until day 8 post-operation (PO) in group B. Half of the animals were euthanized on days 10 and 14 PO, respectively. The remnant liver was weighed and stained by hematoxylin and eosin and immunohistochemical staining of proliferating cell nuclear antigen and epithelial cell adhesion molecule enabled HOC proliferation analysis.

FK506 intervention exacerbated liver damage and hindered the recovery of the HOC model rat. Weight gain was severely retarded or even negative. Liver weight and the liver body weight ratio were lower than control group. HE and immunohistochemistry showed pooer proliferation of hepatocytes and fewer HOC numbers in group A.

FK506 inhibited HOC activation by affecting T and NK cells, ultimately blocking liver regeneration. Poor liver regeneration after auxiliary liver transplantation might be associated with the inhibition of HOC activation and proliferation caused by FK506 treatment.