Aging and its impact onthe quality of grafts: an experimental study in rats livers / O impacto do envelhecimento na qualidade do enxerto: estudo experimental em fígados de ratos

ABSTRACT

CONTEXT: There are consistent clues of worse results with grafts from older donors, especially in hepatitis C. University of Wisconsin (UW) solution is adopted for liver preservation, but other solutions are being studied, as fructose-1,6-bisphosphate (FBP). OBJECTIVE: To determinate the impact of aging of the donor on the cold ischemia injury in rat livers and compare UW and FBP. METHODS: Twenty male Wistar rats were studied - 10, aging 20 weeks: 5 to preservation with UW (C-UW) and 5, FBP (C-FBP); and other 10, aging 50 weeks: 5 to UW (E-UW) and 5 to FBP (E-FBP). Rats were anesthesized, submitted to hepatectomy, and graft was kept under 2-4ºC for 8 hours. Liquid samples were taken at 2, 4, 6, and 8 hours, to determine AST and LDH. At the end, in the liver tissue thiobarbituric acid reactive substances and catalase were determined. RESULTS: Average liver weight was similar between controls and the others (12.5 g ± 1.8 and 13.4 g ± 2.0). AST and LDH levels were higher in C-UW group (P<0.05). In the older group, there was a difference between UW and FBP preserved livers related to LDH, but not to AST. Thiobarbituric acid reactive substances were superior in control group than in the older one (P = 0.001). Catalase activity was similar between these groups (P = 0.11), but it was superior in UW preserved animals (P = 0.02). CONCLUSION: Livers from older rats were similar to the controls regarding cold ischemia injury in FBP group. Surprisingly, with UW solution there was less cold ischemia injury in the elderly group. When comparing both solutions, FBP provided significantly more protection than UW in the controls. There was a trend to FBP to being better than UW in the elderly group. Further studies with liver from older donors and ischemia and reperfusion are needed.

RESUMO

CONTEXTO: Dados da literatura atual sugerem piores resultados quando os transplantes hepáticos são realizados com enxertos provenientes de doadores idosos. O uso da solução Universidade de Wisconsin (UW) é universal; entretanto alternativas como a fructose-1,6-bisfosfato (FBP) vêm sendo estudadas. OBJETIVOS: Determinar o impacto do envelhecimento do doador no dano de isquemia a frio em fígados de ratos, comparando as soluções de FBP e UW. MÉTODOS: Vinte ratos Wistar foram estudados - 10 com 20 semanas: 5 preservados com UW (C-UW) e 5 com FBP (C-FBP); e outros 10, com 50 semanas: 5 com UW (E-UW) e 5 com FBP (E-FBP). A preservação durou 8 horas. Foram dosadas AST e LDH nas alíquotas do líquido de preservação a cada 2 horas. RESULTADOS: Os níveis de AST e LDH foram superiores no grupo (C-UW) (P<0.05). Quando comparadas UW x FBP no grupo de idosos houve diferença quanto à LDH, mas não com a AST. CONCLUSÃO: A preservação dos fígados de ratos idosos foi similar aos dos controles, quando preservados com FBP. Quando utilizada UW, a lesão de preservação foi menor no grupo de ratos idosos. A FBP minimizou a isquemia a frio nos controles, quando comparada a UW. Houve tendência de a FBP ser superior a UW no grupo idosos.