Figure 2. Intracellular accumulation of carbamylated proteins after long-term incubations with urea or cyanate. Confluent fibroblasts were incubated for 4 weeks at 37°C with DMEM + 0.5% (v/v) FBS without (control conditions, open bars) or with 20 mmol/L urea (grey bars) or 0.5 mmol/L cyanate (black bars). HCit content was determined by LC-MS/MS in total cell extracts (a) and in cytoplasmic and membrane fractions (b). The data are presented as means ± SEM (n=6) compared using the Mann-Whitney U test (ns: non significant, **: p<0.01).