Alterações metabólicas induzidas por isquemia hepática normotérmica experimental

Abstract

The complete interruption of the blood flow to the liver is often necessary during operations for hepatic trauma or when extensive ressection to remove a tumor is mandatory. Hepatic transplantation is inevitably associated with periods of complete ischaemia. However, the clamping of the hepatic vascular pedicle is limited by the consequences of the post-ischaemic injury to the liver. Normothermic hepatic ischaemia during sixty minutes was induced in the rat. The time-course (0, 1, 6, 24h) of changes in the blood and the hepatic concentrations of lactate, pyruvate, glucose, ketone bodies and in the ratio of acetoacetate/3-hydroxybutyrate, as well as the cytoplasmic and mitochondrial redox state of the liver cells were determined. A group of animais was pre-treated with cyclosporine (10 mg/Kg i. p.) and another group with ternatin (25 mg/Kg i. p.). and then they were studied 1h after hepatic revascularization. Hepatic ischaemia caused elevation in the concentration of lactate in the liver, suggesting that a pronounced levei of anaerobic metabolism occured during the ischaemia period. Liver ischaemia promoted yet a fali in the concentration and in the ratio of ketone bodies( acetoacetate/3-hydroxybutyrate) in the arterial blood in the studied period of one hour post- revascularization, perhaps reflecting impairment of ketogenesis as a result of the ischaemia injury. The treatment with cyclosporine and ternatin caused elevation in the concentration of ketone bodies and in the ratio acetoacetate/3-hydroxybutyrate in the arterial blood one hour after reperfusion of the liver, suggesting that these drugs may accelerate the recovery of the ischaemic hepatic lesion. It is possible that the utilization of cyclosporine or ternatin in transplant recipients or their use in transplant preserving solutions, may help to improve the results of liver transplantation.