The effect of laser on remanescent liver tissue after 90 percent hepatectomy in rats / Efeito do laser no tecido hepático após hepatectomia a 90 por cento em ratos

ABSTRACT

PURPOSE: To evaluate the effect of laser beam on remanescent liver after partial hepatectomy 90 percent. METHODS: Wistar rats, (N= 42), were divided into six groups with seven specimens each. The partial hepatectomy (HP) was performed in all animals through exeresis of approximately 90 percent of the liver parenchyma. The animals from groups HP and Laser application, HPL24, HPL48 and HPL72 undertook laser irradiation carried out through application (dose of 22.5 J/cm²) in five different sites in the remanescent liver. The rats were then sacrificed 24, 48 and 72hours after HP procedure, for the liver regeneration analysis,using the Proliferating Cell Nuclear Antigen (PCNA),and for dosage of serum aminotransferases. RESULTS: Were demonstrated an increase of the serum levels of alanine aminotransferase for the group of 24 hours and a decrease for the group of 72 hours exposed to laser. The index of marked cells had a considerable more improvement for the group of 72 hours exposed in laser compared to other groups. CONCLUSION: Laser did not cause hepatic injuries additional to the partial hepatectomy and perhaps led to a benefit by stimulating the proliferative activity.

RESUMO

OBJETIVO: Avaliar o efeito da luz laser em remanescentes hepáticos após hepatectomia a 90 por cento. MÉTODOS: Aplicou-se luz laser com comprimento de onda de 660 nm e potência de 30 mw, por 30 segundos, na dose de 22,5 J/cm² em cada um deles, repetidos em cinco pontos do fígado remanescente, após realizada a hepatectomia a 90 por cento. Os animais foram sacrificados para análise do fígado, contagem de hepatócitos em proliferação (Proliferating Cell Nuclear Antigen -PCNA), e coleta de sangue para dosagem serica das aminotransferases, após 24, 48 e 72 horas. RESULTADO: O índice de células marcadas teve significativo aumento no grupo de 72 horas irradiados com laser. CONCLUSÃO: A análise dos resultados demonstrou que o laser não causou lesões hepáticas adicionais à hepatectomia parcial e estimulou a atividade proliferativa hepatocelular.