Beneficial effect of alanine on metabolic recovery of fasted livers submitted to cold ischemia

Effect of nutritional state of brain-dead organ donor on transplantation

OBJECTIVE

We describe the effect of the metabolic and nutritional modifications caused by severe illness or injury in brain-dead organ donors on transplant organ function. Malnutrition is frequently found in brain-dead organ donors and nutrients may interfere with different organ functions.

METHODS

Literature was obtained from MEDLINE using the key words organ donation, brain death, transplantation, nutrition, fish oil, amino acids.

RESULTS

In the liver, infusion of large quantities of dextrose can restore glycogen reserves but may induce hyperglycemia and a hyperosmolar hepatic state. Feeding improves protein synthesis in hepatocytes, and fat (fish oil) administration in particular increases the hepatic energy and adenosine triphosphate content. Amino acids have a significant effect on regenerating hepatic tissue when given with fat and glucose. In the heart, free fatty acids administered during reperfusion improve cardiac functional recovery, and administration of propofol, a general anesthetic agent enriched with fatty acids, have protective effects on ischemia-and-reperfusion injury. Glutamine also can induce graft protection during ischemia-and-reperfusion injury. Renal function is improved by fish oil supplementation. In addition, effective renal plasma flow, glomerular filtration rate, and renal blood flow are increased, apparently by a reduction in thromboxane B2 production. Glycine or alanine can protect renal tubules from stress injury.

CONCLUSION

Nutrition plays an important role in the modulation of organ function after transplantation.

The effect of dichloroacetate and alanine on the metabolic recovery of perfused mouse liver after cold ischemia

Pyruvate dehydrogenase has been thought to be involved in the improved recovery of livers, from fasted donors, reperfused with alanine after cold preservation. The aim of this work was to investigate the effect on perfused mouse liver of dichloroacetate, an activator of this enzyme. Livers from fed and fasted animals were perfused with oxygenated Krebs-Henseleit buffer for 30 min, then stored at 4 degrees C in University of Wisconsin solution for 48 h. Then reperfusion at 37 degrees C was performed with Krebs-Henseleit buffer containing 2 mM dichloroacetate for 1 h. (3-(13)C)Alanine (8 mM) was then added and perfusion was continued for a second hour. (31)P-NMR was used to measure nucleoside triphosphate recovery of the livers. At the end of reperfusion, (13)C-NMR spectra of perfusates were recorded. Dichloroacetate (DCA) was found to activate pyruvate dehydrogenase in all cases. However, it decreased the functional recovery of livers from both fed and fasted mice. In order to study the effect of alanine on this DCA deleterious effect, we reperfused the livers according to a modified protocol. The first hour of perfusion without alanine was omitted and the organs were reperfused directly for 1 h in the presence of 2 mM dichloroacetate and 8 mM (3-(13)C)alanine. In this protocol, the deleterious effect of DCA was completely suppressed for livers from fasted mice. These results led to the conclusion that the specific beneficial effect of alanine on livers from fasted livers persists in the presence of DCA and thus cannot be explained solely by the induction of a greater pyruvate dehydrogenase reaction rate.