Figure 1. Urea Synthesis Rates in Primary Porcine Hepatocytes Cultured in Four Separate Chemically-Defined Media Formulations.

Urea synthesis rates of porcine hepatocytes cultured at 10⁷ viable cells per 100 mm dish in WE, ML-15, M199 and M1640 chemically-defined media for up to 6 days. 2 mM NH₄Cl was added to culture dishes and incubated for 2 hours on days 2, 4 and 6. USR was determined in media samples taken at 0 and 2 hours using a modified colourimetric urea nitrogen kit as described above. Results are expressed as nmol/hour/mg total protein. All values represent the means ± SEM of nine experiments in duplicate. Statistics: Day 2: WE vs M1640, p = 0.044; M199 vs M1640, p = 0.015; Day 4: WE vs M1640, p = 0.010; M199 vs M1640, p = 0.001; Day 6: ML-15 vs M1640, p = 0.031; M199 vs M1640, p = 0.055.