Efeito do exercício físico na prevenção da lesão de isquemia reperfusão hepática

Abstract

Ischemia-reperfusion injury is a common adverse event of liver surgery and occurs as a consequence of the need to control bleeding risk. This injury results from a direct cellular damage caused by the ischemia resulting from the interruption of blood flow, which is then accentuated during the reperfusion phase of the organ. Liver ischemia-reperfusion injury is frequent and contributes significantly to the increased risk of morbidity and mortality after liver surgery. Currently there are no effective strategies for its prevention. There is evidence that physical exercise induces adaptations that provide protection against ischemia-reperfusion injury, particularly in the myocardium. However, it is not known if physical exercise is also effective in the development of similar adaptations in the liver. The aim of this study was to determine whether a 15-day exercise protocol is effective in reducing cell damage resulting from liver ischemia-reperfusion injury. The experiments were carried out on n=27 male Wistar rats with approximately 10 weeks of age. Rats were divided into 4 experimental groups according to whether they were exercised or not (sedentary vs exercised) and according to whether they were submitted or not to liver ischemia-reperfusion injury (ischemia-reperfusion vs sham). Twenty-four hours after induction of ischemia-reperfusion injury, animals were sacrificed and the liver and soleus muscles collected for morphometric and histological analysis. Results found showed that the physical exercise protocol performed prior to the ischemia-reperfusion injury did not produced significant protective effects against liver ischemia-reperfusion injury, as the degree of liver damage found in exercised animals was identical to that of sedentary animals. With this study, it was possible to conclude that the ischemia and reperfusion protocol used induced liver damage, but that the 15 days training protocol was not effective in preventing liver damage identified 24 hours after reperfusion.