Table 2.

Physiological Concentrations of Metabolites in Murine Liver Used in the Simulations

metabolite	concentration (µM)	reference
cysteinea	100	15,33,53,61
cystine	0.2	15
homocysteine	1.25	61
homocystineb	0.06	–
cystathionine	8.0	61
serine	560	62

^aThe study reporting hepatic cystine concentrations of 0.20 ± 0.01 µM reported a cysteine concentration of 68 ± 17 µM.15 Other studies have reported hepatic cysteine concentrations of 129 ± 12 µM,53 115 ± 52 µM³³ and 75 ± 3 µM⁶¹ leading to the average value of 100 µM used here.

^bThe concentration of homocystine in murine liver has not been reported to our knowledge. We arbitrarily set the concentration of homocystine to be 5% of the homocysteine concentration.