Effect of ALR and LPS on Kupffer cells and hepatocytes. (A) Kupffer cells (KC) were incubated with carrier (PBS), 50 nM rrALR or 100 ng/ml LPS for 24 h. The medium (KC to HC) was transferred to hepatocytes (HC). Control hepatocytes were incubated with 50 nM ALR or 100 ng/ml LPS. At 24 h, DNA synthesis (3H]thymidine) incorporation assay was performed. While KC-conditioned medium inhibited DNA synthesis in HC, the effect was reversed or augmented when KC were conditioned with ALR or LPS, respectively. ALR or LPS, on their own, did not affect HC DNA synthesis, while 5 nM TGF-α exerts robust effect. (B, C) Kupffer cells were incubated in the presence of 100 ng/ml LPS or 50 nM rrALR for 24 h. The medium was aspirated and TNF-α (B) or nitric oxide product NO2 (C) were measured. *P ≪ 0.05 vs. vehicle; **P ≪ 0.01 vs. vehicle or 0.05 vs. ALR; ***P ≪ 0.001 vs. vehicle or ALR (see  for details of the procedures).