Ischemic preconditioning vs adenosine vs prostaglandin E1 for protection against liver ischemia/reperfusion injury

Ischemia/reperfusion injury is still a major cause of morbidity and mortality during liver surgery and transplantation. A variety of surgical and pharmacological therapeutic strategies have been investigated to minimize the effects of ischemia/reperfusion. The aim of our study was to analyze and compare preventive influences of ischemic preconditioning, adenosine and prostaglandin E1 in the experimental model of hepatic ischemia/reperfusion injury. Adult chinchilla rabbits were divided into four groups: 10 rabbits subjected to liver ischemic preconditioning (3-min period of inflow occlusion followed by a 5-min period of reperfusion) followed by 45 min of Pringle maneuver; 10 rabbits subjected to pre-treatment with intraportal injection of adenosine followed by 45 min of Pringle maneuver; 10 rabbits subjected to pre-treatment with intraportal injection of prostaglandin E1 followed by 45 min of Pringle maneuver; and control group of 10 rabbits subjected to 45 min of inflow liver ischemia without any preconditioning. On the second postoperative day, blood samples were obtained and biochemical parameters of liver function were measured and compared. Liver tissue samples were also obtained and histopathological changes were compared. Based on biochemical and histopathological parameters, it was demonstrated that ischemic preconditioning provided the best protection against hepatic ischemia/reperfusion injury. This was probably due to a wider range of mechanisms of action of this method oriented to reduce oxidative stress and inflammation, and restore liver microcirculation and hepatocyte energy compared to the examined pharmacological strategies.

Cytochemical & ultrastructural alteration of cytoplasmic granules of rat peripheral blood neutrophils induced by chronic alcoholism & malnutrition.

The specific influence of malnutrition on the pathophysiologic changes induced by chronic alcoholism is controversial. In an attempt to determine and demarcate the effects of protein malnutrition from those produced by alcoholism and to evaluate the precise effect of alcohol per se on cytochemical and ultrastructural properties of rat polymorphonuclear neutrophil (PMN) granules, we investigated the influence of chronic protein malnutrition or chronic alcoholism alone and in combination, in rats. After a 4 month experimental period various PMN properties, such as cytochemical, morphometrical and ultrastructural, as well as neutrophil functions were studied. It was found that the degree of damage of PMNs induced either by ethanol or protein malnutrition alone was similar whereas their combination led to worsening of all markers of PMN functional ability. Ultrastructural changes of neutrophil granules including reduction, redistribution and atypical accumulation as well as appearance of autophagic vacuoles, confirmed their alteration which was emphasised by the additive pathophysiological interaction of alcoholism and chronic hypoprotein malnutrition.