Subcellular Transfer of Reducing Equivalents in the Neuronal and Glial Compartments of the Adult Rat Brain After Portocaval Anastomosis and Chronic Moderate Hyperammonemia as Detected by (13C, 2H) NMR

Tiago Brandao Rodrigues¹, Regina Rodrigo², Omar Cauli², Vicente Felipo², Sebastin Cerdn¹

We report on the effects of portocaval anastomosis and chronic moderate hyperammonemia on the transfer of reducing equivalents between the cytosolic and mitochondrial compartments from the neurons and astrocytes of the adult rat brain using a novel (¹³C, ²H)NMR approach. The administration of ²H₂O to the animals allowed detecting and quantifying the presence of [2-¹³C], [2-¹³C,3-²H] and [2-¹³C,3,3-²H₂]isotopomers of glutamate and glutamine. Portocaval anastomosis results in an evident limitation in the transfer of reducing equivalents between cytosol and mitochondria of the neuronal and glial compartments, whereas hyperammonemia didnt affect substantially this transport of reducing equivalents, both in the mitochondrial and the cytosolic compartments.