RESUMO
Intermittent clamping of the portal trial is an effective method to avoid excessive blood loss during hepatic resection, but this procedure may cause ischemic damage to liver. Intermittent selective clamping of the lobes to be resected may represent a good alternative as it exposes the remnant liver only to the reperfusion stress. We compared the effect of intermittent total or selective clamping on hepatocellular injury and liver regeneration. Entire hepatic lobes or only lobes to be resected were subjected twice to 10 min of ischemia followed by 5 min of reperfusion before hepatectomy. We provided evidence that the effect of intermittent clamping can be damaging or beneficial depending to its mode of application. Although transaminase levels were similar in all groups, intermittent total clamping impaired liver regeneration and increased apoptosis. In contrast, intermittent selective clamping improved liver protein secretion and hepatocyte proliferation when compared with standard hepatectomy. This beneficial effect was linked to better adenosine-5'-triphosphate (ATP) recovery, nitric oxide production, antioxidant activities and endoplasmic reticulum adaptation leading to limit mitochondrial damage and apoptosis. Interestingly, transient and early chaperone inductions resulted in a controlled activation of the unfolded protein response concomitantly to endothelial nitric oxide synthase, extracellular signal-regulated kinase-1/2 (ERK1/2) and p38 MAPK activation that favors liver regeneration. Endoplasmic reticulum stress is a central target through which intermittent selective clamping exerts its cytoprotective effect and improves liver regeneration. This procedure could be applied as a powerful protective modality in the field of living donor liver transplantation and liver surgery.
Assuntos
Estresse do Retículo Endoplasmático , Retículo Endoplasmático/metabolismo , Hepatectomia , Circulação Hepática , Regeneração Hepática , Fígado/irrigação sanguínea , Fígado/cirurgia , Estresse Oxidativo , Traumatismo por Reperfusão/prevenção & controle , Trifosfato de Adenosina/metabolismo , Animais , Antioxidantes/metabolismo , Apoptose , Proliferação de Células , Constrição , Retículo Endoplasmático/patologia , Peroxidação de Lipídeos , Fígado/metabolismo , Fígado/patologia , Fígado/fisiopatologia , Masculino , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Óxido Nítrico/metabolismo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologia , Transdução de Sinais , Fatores de Tempo , Resposta a Proteínas não DobradasRESUMO
Sixty-six extracts of 18 plants commonly used by traditional healers in Congo Brazzaville for the treatment of malaria have been investigated for in vitro antiplasmodial activity. Ethanolic and dichloromethane extracts of 7 among the 18 studied plants were moderately active (10 microg/mlAssuntos
Antimaláricos/isolamento & purificação
, Antimaláricos/farmacologia
, Medicinas Tradicionais Africanas
, Plantas Medicinais
, Linhagem Celular Tumoral
, Congo
, Eritrócitos/efeitos dos fármacos
, Eritrócitos/parasitologia
, Humanos
, Extratos Vegetais/isolamento & purificação
, Extratos Vegetais/farmacologia
, Estruturas Vegetais