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Pulmonary neutrophil entrapment and resultant oxidative injury is thought to be the primary mechanism of cardiopulmonary bypass (CPB) induced lung injury. Interleukin-8 (IL-8), a potent neutrophil chemoattractant induced by cytokines, including tumor necrosis factor-alpha (TNF), is found in increased concentrations in bronchial alveolar lavage fluid (BALF) in lung inflammation. Since aprotinin reduces TNF release during CPB, the effects of aprotinin on BALF IL-8 concentrations and neutrophil levels were determined after CPB in adult humans. Study patients were equally divided into a control group (n = 8, Group 1) and an aprotin-intreated group (n = 8, Group 2). In vitro neutrophil chemotaxis was done with volunteer neutrophils using three different chemoattractants: 1) N-formyl-1-methionyl-1-leucyl-1-phenylalanine (FMLP); 2) the supernatant of a human bronchial epithelial cell culture line, A549, after 24 h of TNF stimulation with or without aprotinin or N-alpha-tosyl-L-lysine chloromethyl ketone (TLCK) (a potent protease inhibitor), and 3) BALF. Aprotinin treatment significantly (P < 0.05) reduced post-CPB BALF IL-8 concentrations and percentage of neutrophils. In vitro, BALF from Group 1 had significantly greater chemotactic ability when compared with Group 2. The TNF stimulated A549 cell culture supernatant had significantly (P < 0.05) greater chemotactic ability than control supernatant, while aprotinin and TLCK significantly (P < 0.05) reduced this chemotactic ability. These results demonstrate that aprotinin blunts IL-8 production and reduces neutrophil lung accumulation post-CPB.

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We investigated how the protection of energy status by isoflurane in isolated hepatocytes varied with isoflurane dose, duration of anoxia, and reoxygenation. Hepatocytes were isolated from fed rats and incubated in Krebs buffer under O2/CO2 or N2/CO2 (95/5) for 30 or 90 min, followed by 5 or 30 min of reoxygenation. From measurements of adenosine tri-, di-, and monophosphate (ATP, ADP, AMP) in the cells, energy charge (= [ATP + 1/2 ADP]/[ATP + ADP + AMP]) was calculated to reflect the balance between ATP supply and demand, and total adenine nucleotide (= ATP + ADP + AMP) to indicate the potential maximum ATP level. During 30 min of anoxia, energy charge and total adenine nucleotide steadily increased with isoflurane dose from 0 to 2 minimum alveolar anesthetic concentration, then decreased from 2 to 3 minimum alveolar anesthetic concentration. In short incubations (30-35 min) at 1 minimum alveolar anesthetic concentration isoflurane, there was a modest decrease in energy charge during anoxia, partially prevented by isoflurane and completely reversed by reoxygenation, and no decrease in total adenine nucleotide. In long incubations (90-120 min), there were large decreases in both energy charge and total adenine nucleotide during anoxia, with partial and no reversal by reoxygenation, respectively. Isoflurane partly prevented decreases in both energy charge and total adenine nucleotide during both anoxia and reoxygenation. We conclude that at doses in the clinical range, isoflurane partially protected isolated hepatocytes against decreases in both energy charge and total adenine nucleotide occurring either during short (reversible) or long (irreversible) anoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

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The enzyme xanthine: acceptor oxidoreductase found in rat heart equilibrates between three forms differing in electron acceptor specificity. Form D transfers electrons exclusively to NAD+ and accounts for 85% of total oxidoreductase activity. Form O transfers electrons to molecular oxygen and accounts for 8%. The D/O form prefers NAD+, but without NAD+ transfers electrons to oxygen. Interconversion from D to O and O to D forms is catalyzed by sulfhydryl group-modifying reagents: Cd2+, Cu2+, disulfiram, and heating with dithiothreitol. This suggests that sulfhydryl groups participate in the first stage of enzyme conversion. The NADH/NAD+ concentration ratio may regulate the dehydrogenase activity of xanthine:acceptor oxidoreductase (NAD+-dependent activity of D and D/O forms). Accumulating NADH inhibits hypoxanthine hydroxylation. The amount of form O increases during cardiac ischemia, facilitating superoxide radical-ion generation. Also, NADH/NAD+ does not regulate form O, promoting adenylate nucleotide pool depletion, especially in the heart which has low de novo purine nucleotide synthesis.

Both cold and warm ischemia occur during liver transplantation. Hypothermia and Wisconsin solution preserve adenine nucleotide energy status, which is crucial to hepatic function and viability. The volatile anesthetic isoflurane has been shown to preserve energy status in anoxic isolated hepatocytes in warm Krebs solution. The present study examined isoflurane effects on energy status during incubation also in Wisconsin or Krebs-plusadenosine solution at 37" or 4". Hepatocytes were isolated from rat liver after perfusion with Krebs + collagenase. In 25-mL flasks, 12.5 million cells in 2.5 mL of Krebs, Krebs plus 5 mmol/L adenosine, or Wisconsin solution were incubated under an atmosphere of 02/C02 or N2/CO2(19:1) & isoflurane (3 volumes% = 2ED50), for 30 minutes at 37°C or 4°C. Adenine nucleotides were measured uring liver transplantation, both cold and warm D anoxia and ischemia occur during procurement and implantation of the donor liver. Lack of oxygen inhibits adenosine triphosphate (ATP) formation by oxidative phosphorylation. Anaerobic glycolysis, even though maximally activated, is less efficient at forming ATP; consequently, there is a decline in cellular ATP levels and other measures of energy status such as energy charge (EC) and total adenine nucleotide level (TAN). The importance of these changes is indicated by evidence that the liver's ability to maintain or regain energy balance during and after surgical or anoxic insult predicts subsequent function and viability. have not been correspondingly well studied. Such information could be important to understanding the mechanism(s) by which UW preserves liver during ischemia and anoxia.6The volatile anesthetic isoflurane, at concentrations used clinically, has been shown to partially preserve energy status in isolated hepatocytes in Krebs buffer during warm anoxia.' During both short/reversible (30 minutes) and long/irreversible (90 minutes) anoxia, ATP, EC, and TAN values were significantly higher in the presence than in the absence of isoflurane (1.5 to 3 volumes per cent [vol%] ; 1-2 ED50; 1-2 MAC [mean alveolar concentration for surgical anesthesia]).* We studied how energy status was affected by exposure to isoflurane along with different incubation solutions and temperatures. Materials and MethodsApproval was obtained from the institutional animal care and use committee for preparation of hepatocytes from the livers of fed adult male Sprague Dawley rats weighing 275 g to 350 g. Animals were allowed free access to food and water before being anesthetized with pentobarbital 50 mg/kg intraperitoneally (IP). Recirculating perfusion of the liver was established in situ, with the portal vein cannulated for inflow and the inferior vena cava (using a transatrial approach) for outflow. Perfusion was camed out for 5 minutes at a flow rate of 35 to 40 mL/min using Ca2+-free Krebs-Henseleit buffer equilibrated with Or/C02(95/5 ~01%) at