Lesão de isquemia e reperfusão após clampagem contínua ou intermitente do pedículo hepático em coelhos

Abstract

-Background -The control of bleeding in hepatectomy is a challenge for surgeons. The hepatic pedicle clamping is a surgical maneuver that can provide reduction in bleeding, but it provokes a hepatocellular suffering. This, along with reperfusion after the clamping finishes, leads to an injury known as ischemia/reperfusion injury. Aim -To examine the effects of the ischemia/reperfusion injury on the liver after continuous and intermittent hepatic pedicle clamping in an animal model, using the quantification of apoptosis for evaluation. Method -Twenty New Zealand rabbits were assigned to groups 1 (control), 2 (60 minutes of continuous ischemia) and 3 (60 minutes of intermittent ischemia alternating 12 minutes of ischemia and three minutes of reperfusion). Liver biopsies were collected before ischemia, at its end and after six hours of reperfusion, when the animals were killed. The liver fragments were subjected to histological analysis (paraffinization and hematoxilin-eosin staining) and histochemical (Tunel reaction). Microscope fields of view were scanned for characterization and quantification of apoptosis. Results -Ischemia led to an increased apoptotic index in both experimental groups in comparison to controls, but similarly between them. After the reperfusion, the indexes returned to baseline values. Conclusion -Clamping of the hepatic pedicle, either continuous or intermittent, induces apoptosis in liver cells in a similar way. ABCDDV/852RESUMO -Racional -O controle do sangramento na hepatectomia é um desafio para os cirurgiões. A clampagem do pedículo hepático é manobra cirúrgica que pode promover redução do sangramento, mas provoca isquemia hepatocelular. Isso, junto com a reperfusão depois que a clampagem termina, leva à lesão de isquemia e reperfusão. Objetivo -Examinar os efeitos da lesão de isquemia e reperfusão no fígado após clampagem contínua e intermitente do pedículo hepático, usando a quantificação de apoptose como ferramenta. Método -Vinte coelhos New Zealand foram divididos em grupos 1 (controle), 2 (60 minutos de isquemia contínua) e 3 (60 minutos de isquemia intermitente alternando 12 minutos de isquemia e três minutos de reperfusão). Biópsias hepáticas foram colhidas antes e ao fim da isquemia e após seis horas de reperfusão, quando os animais eram sacrificados. Os fragmentos obtidos foram submetidos à análise histológica e histoquímica (reação de Tunel). Campos microscópicos foram analisados para caracterização e quantificação de apoptose. Resultados -A isquemia levou à elevação do índice apoptótico em ambos os grupos experimentais em relação aos controles, mas similar entre eles. Depois da reperfusão os índices voltaram aos valores iniciais. Conclusão -A clampagem do pedículo hepático, tanto contínua quanto intermitente, induz a apoptose em células hepáticas de modo igual.

Epigallocatechin Gallate Does Not Accelerate the Early Phase of Liver Regeneration After Partial Hepatectomy in Rats

“…Paraffin sections were stained with hematoxylin & eosin and checked for the presence of steatosis and/or inflammation. Furthermore, apoptosis was assessed according to [34], i.e., the number of apoptotic bodies per visual filed was calculated in hematoxylin & eosin-stained samples. The pathologist evaluating the samples was blinded to the study.…”

Trisulfate Disaccharide Decreases Calcium Overload and Protects Liver Injury Secondary to Liver Ischemia/Reperfusion

“…Ischemia-reperfusion (I/R) injury remains a major problem in various clinical situations, including trauma, shock, hemorrhage, liver resection, and transplantation [ 1 , 2 ]. Current therapeutic procedures, such as ischemic pre or post conditioning and intermittent vascular occlusion, can minimize but not prevent hepatic I/R injury [ 3 – 6 ]. Up to the present time, although many compounds have been tested, only a few drugs have been shown to ameliorate or diminish liver I/R injury [ 7 – 8 ].…”