The role of polyamines in liver regeneration after hepatectomy with ischemic injury.

A total of 175 rats were divided into: (1) a sham operation group, in which the liver was slightly mobilized after laparotomy; (2) a control group in which 68% of the liver was resected without the blockade of blood flow; (3) an ischemia + hepatectomy group, in which the vessels entering the right and caudate lobes were clamped for 30 min, and the nonischemic lobes were resected; (4) a DFMO + ischemia + hepatectomy group, in which the same procedure as for the ischemia + hepatectomy group was performed, but the animals received alpha-difluoromethylornithine (DFMO); (5) a DFMO + Put + ischemia + hepatectomy group, in which the animals underwent the same procedure, but were given putrescine (Put) in addition to DFMO. There were 6 to 7 rats in each of the five groups. The putrescine level and ornithine decarboxylase (ODC) activity were significantly higher in the ischemia + hepatectomy group than in the control group, but were markedly decreased in the DFMO + ischemia + hepatectomy group. However, the lipid peroxide level was significantly higher in the DFMO + ischemia + hepatectomy group than in the ischemia + hepatectomy group. The incorporation of [3H]thymidine in the DFMO + ischemia + hepatectomy group was significantly lower than that in the control group. The increase in the lipid peroxide level and the decrease in [3H]thymidine found in the DFMO + ischemia + hepatectomy group tended to be reversed by the administration of putrescine. These results suggest that putrescine suppressed the production of lipid peroxides and promoted DNA synthesis in regenerating the liver after ischemia-reperfusion injury.