Hepatotrophic effect of cyclosporine and FK 506 is not mimicked by rapamycin

Assessment of Effect of Intraperitoneal Tacrolimus on Liver Regeneration in Major (70%) Hepatectomy Model After Experimental Pringle Maneuver in Rats

AIM

Small-for-size grafts have become more important, especially in living donor liver transplants. The Pringle maneuver, used to reduce blood loss, and the immunosuppressive medications used to prevent graft rejection in liver transplants have different side effects on liver regeneration. We researched the effect of situations where tacrolimus and the Pringle maneuver were applied or not on liver regeneration in rats with partial hepatectomy.

MATERIAL AND METHODS

This study was completed with 35 Wistar Albino rats. The subjects were randomly divided into 5 groups: Group 1 had the abdomen opened and no other procedure was performed; Group 2 underwent a 70% hepatectomy; Group 3 underwent a 15-minute Pringle maneuver + 70% hepatectomy; Group 4 underwent a 70% hepatectomy + 5 days of 1 mg/kg/day intraperitoneal tacrolimus; and Group 5 underwent a 150 minute Pringle maneuver + 0% hepatectomy + 5 days of 1 mg/kg/day intraperitoneal tacrolimus. All rats were sacrificed on the seventh postoperative day, remaining liver tissue was weighed, and weight indices created. The remaining liver tissue was stained with phosphohistone H3 and the mitotic index calculated.

RESULTS

The groups that underwent the Pringle maneuver, 70% hepatectomy, and tacrolimus administration were compared with the control group in terms of mitotic index and weight index, but no statistically significant differences were identified.

CONCLUSION

Suppression of regeneration forms a risk after liver transplantation with small-volume grafts. As a result, research on the effect of tacrolimus combined with the Pringle maneuver is important, especially for transplantations using segmented liver grafts. In our study, we showed that the use of tacrolimus had no negative effect on liver regeneration.

Sirolimus influence on hepatectomy-induced liver regeneration in rats

OBJECTIVE: To evaluate the influence of sirolimus on liver regeneration triggered by resection of 70% of the liver of adult rats. METHODS: we used 40 Wistar rats randomly divided into two groups (study and control), each group was divided into two equal subgroups according to the day of death (24 hours and seven days). Sirolimus was administered at a dose of 1mg/kg in the study group and the control group was given 1 ml of saline. The solutions were administered daily since three days before hepatectomy till the rats death to removal of the regenerated liver, conducted in 24 hours or 7 days after hepatectomy. Liver regeneration was measured by the KWON formula, by thenumber of mitotic figures (hematoxylin-eosin staining) and by the immunohistochemical markers PCNA and Ki-67. RESULTS: there was a statistically significant difference between the 24h and the 7d groups. When comparing the study and control groups in the same period, there was a statistically significant variation only for Ki-67, in which there were increased numbers of hepatocytes in cell multiplication in the 7d study group compared with the 7d control group (p = 0.04). CONCLUSION: there was no negative influence of sirolimus in liver regeneration and there was a positive partial effect at immunohistochemistry with Ki-67.

Cyclosporine A, FK-506, 40-0-[2-hydroxyethyl]rapamycin and mycophenolate mofetil inhibit proliferation of human intrahepatic biliary epithelial cells in vitro

AIM

To investigate the effect of cyclosporine A (CsA), FK-506, and mycophenolate mofetil (MMF) and 40-0-[2-hydroxyethyl]rapamycin (RAD) on proliferation of human intrahepatic biliary epithelial cells (BECs) in vitro.

METHODS

BECs were isolated from six human liver tissuespecimens with the immunomagnetic separation method and treated with different concentrations of CsA, FK-506, RAD, and MMF in vitro. Proliferation of the cells was measured by MTT assay at 24 and 48 h after treatment, respectively. One-way analysis of variance was used to analyze the results. Expression of CK 19 in BECs was monitored by flow cytometry and Western blot.

RESULTS

Six lines of BECs were established. They survived for 4-18 wk in vitro. Flow cytometry analysis showed that these cells always expressed CK19. CsA, FK-506, RAD, and MMF inhibited proliferation of BECs in a dose-dependent manner. The lowest concentration of CsA, FK-506, RAD, and MMF to inhibit proliferation of BECs (P<0.05) was 500, 100, 0.25, and 100 mug/L, respectively. However, the expression of CK19 by BECs was not changed.

CONCLUSION

CsA, FK-506, RAD, and MMF have an antiproliferative effect on human intrahepatic BECs in vitro, while RAD has the strongest growth-inhibitory effect. Their possible effects on liver regeneration and bile duct injury in transplant patients should be further investigated.