Fig. 5
From: Metabolic characterization of the natural progression of chronic hepatitis B
Cellular NADH shuttles and the urea cycle. The interplay between a the reduced G3P–NADH shuttle and b a stressed aspartate–malate NADH shuttle and its influence on c the urea cycle. The aspartate transporter AGC (aka citrin) facilitates the transport of aspartate across the mitochondrial membrane to the cytosol where it binds to citrulline in the urea cycle to help detoxify ammonium. Ineffective aspartate transport will lead to the accumulation of glutamate, citrulline, and ornithine identified in the IC and ENEG clinical phases of HBV infection