Fig. 1
From: Effects of a high protein diet and liver disease in an in silico model of human ammonia metabolism

Model of nitrogen metabolism and excretion. NH3 in the figure includes both ammonia and ammonium ions. Circles represent reactions (see Table 1 for reaction equations) and ovals represent reactants and products. a Conceptual framework of the in vivo physiology simulated including the many tissues and subcellular compartments involved. b The system is modeled in silico considering only the concentrations of metabolites in the blood. Abbreviations are as follows: GLUL, glutamine synthetase; Gln, glutamine; GLS, glutaminase; CPS1, carbamoyl phosphate synthetase 1; Urea ex, urea excreted; NH3 abs, ammonia absorbed; NH3 ex, ammonia excreted