Fig. 1: The biochemical background of ureagenesis determination.
From: Characterization and treatment monitoring of ureagenesis disorders using stable isotopes
A Fate of 15NH4+ tracer after oral ingestion; the exogenous labeled tracer molecule (in red) here shown as “NH4+” at entry of the urea cycle and as “NH2” in intermediate urea cycle metabolites and urea. B Design of the ureagenesis assay used in this study. ARG: arginase 1; ASAT: aspartate aminotransferase; ASL: argininosuccinate lyase; ASS argininosuccinate synthetase, CAVA carbonic anhydrase VA, CTRN citrin (mitochondrial aspartate glutamate carrier 2), CPS1 carbamoylphosphate synthetase 1, GDH glutamate dehydrogenase, GLYS glycine synthase (in order to simplify the pathway and focus only in main ammonia metabolism, the glycine cleavage system was omitted here), GS glutamine synthetase, NAGS N-acetylglutamate synthase, ORNT1 mitochondrial ornithine transporter 1, OTC ornithine transcarbamylase.
