Fig 4. Effects of NH₄Cl exposure on human primary hepatocytes.

Following treatment with NH₄Cl, several parameters were determined in cell culture supernatant: A, Cell viability showed no significant differences between various treatment groups (0; 0.1; 1; 10 mM NH₄Cl for 24 h) compared to non-treated control cells as assessed by MTT assay. B, Albumin secretion was quantified by ELISA. While control cells secreted 1944 ± 235 μg/L albumin in 24 hours, cells treated with 10 mM NH₄Cl secreted only 1471 ± 25 μg/L and after 48 hours controls secreted 2820 ± 464 μg/L versus 1666 ± 53 μg/L in treated cells. C, Quantification of urea: while in untreated hepatocytes urea in supernatant increases slightly from 0.42 mmol/L at 24 h to 0.64 mmol/L at 48 h, in NH₄Cl-treated cells urea production increases from 0.82 mmol/L to 1.31 mmol/L, respectively. D, Quantification of ASAT reveals a potential negative effect of ammonia on mitochondrial integrity.