Effect of ulinastatin donor-pretreatment on liver graft during cold preservation in rats.

Background: Donor-pretreatment with ulinastatin may influence the liver graft during cold preservation. The aim of this research was to determine whether pretreatment of donor liver with Ulinastatin can attenuate cold preservation injury, and to explore the mechanism by which Ulinastatin affects the donor liver graft.

Methods: One hundred and forty-four Wistar rats were divided into the Ulinastatin treatment group (T group) pretreated with Ulinastatin 50 000 U/kg and control group (C group) treated with 0.9% normal saline via peritoneal injection prior to the anesthetization. After the abdominal cavity was opened and perfused with cold Ringer's lactate solution, the liver was harvested. The harvested liver was preserved in cold Ringer's lactate solution for 0, 2, 6, 24 hours, at which time the liver tissue was sampled for determination of dry weight and wet weight, Na(+)-K(+)-ATPase and Ca(2+)-ATPase activity, lactic acid dehydrogenase (LDH) activity, lactic acid and malondialdehyde levels. Light microscopy and electron microscopy were used to observe liver morphology. The liver cold-preservation solution was taken for measurement of aspartate aminotransferase (AST) and alanine transaminase (ALT) levels. Correlation between ATPase activity and lactic acid level was analyzed by SPSS 13.0 for Windows.

Results: The morphology in the T group had improved cell boundaries vs. the C group at each time point. Dry weight to wet weight in the T group was lower than in the C group at 6 hours (P < 0.05), but the difference was not significant at 24 hours. ALT levels in the T group were lower than that in the C group at 6 hours (P < 0.05) and 24 hours (P < 0.01). AST levels in the T group were lower than those in the C group at 2 hours (P < 0.05), 6 hours (P < 0.01) and 24 hours (P < 0.01). Na(+)-K(+)-ATPase activity in the T group was higher than in the C group and the mean difference between two groups was significant at 0 hour (P < 0.05) and 2 hours (P < 0.05). Ca(2+)-ATPase activity in the T group was higher than in the C group with the mean difference between two groups significant at 2 hours (P < 0.05). The T group had increased lactic acid levels at 0 hour (P < 0.01) and 2 hours (P < 0.05) compared with the C group, but there was no influence on the LDH activity at the same time. There were no obvious differences in the levels of malondialdehyde between the two groups at any time point. A linear correlation between Na(+)-K(+)-ATPase activity and lactic acid levels (r = 0.295, P < 0.05) was found.

Conclusions: Donor-pretreatment with ulinastatin may protect the cells in a liver graft from ischemia injury during cold preservation; the mechanism may be due to its promotion for cell glycolysis and its preservation of ATPase activity.