Carbohydrate handling enzymes in fetal Down syndrome brain.

Impaired glucose metabolism in adult Down Syndrome (DS) has been well-documented in vivo and information on the underlying biochemical defect i.e. aberrant glucose handling enzymes is already available. Nothing is known on carbohydrate handling, however, in early life of DS patients, when no secondary phenomena as e.g. Alzheimer-like neuropathology occur in the brain yet. We therefore determined a series of key enzymes of carbohydrate metabolism in fetal control and DS brain during the early second trimenon. We used two-dimensional electrophoresis with subsequent MALDI characterization and specific software for quantification of protein spots. We observed comparable levels of phosphoglycerate mutase, phosphoglycerate kinase 1; fructose-biphosphate aldolase A, fructose bisphosphate aldolase C; ribose-phosphate pyrophosphokinase 1; D-phosphoglycerate dehydrogenase, 6-phosphogluconolactonase; aflatoxin B1 aldehyde reductase 1, aldose reductase; inosine-5 ' -monophosphate dehydrogenase 2; galactokinase, in brain of fetal controls and DS. We conclude that our biochemical findings point to the fact that DS patients start early life with unchanged glucose handling, pentose phosphate shunt, glycolysis, sugar aldehyde, guanine nucleotide- and ribonucleoside formation and galactose metabolism.