Figure 10.

Effect of retinoic acid and ET-1 or sarafotoxin S6c on collagen synthesis. (a) HSC were incubated with 2.5 μM retinoic acid or the vehicle (ethanol, 1 μl ml⁻¹) without or with ET-1 (50 nM) or sarafotoxin S6c (SFX) (50 nM) for 10–12 days. Incubations were also performed with ET-1 in the presence of 10 μM BQ-123 or BQ-788. [³H]proline incorporation into the cellular proteins (a) or collagenase-sensitive secreted proteins (b) was determined. Cellular DNA concentration was measured in separate wells by Hoechst's method. (a) ^*P<0.001 vs control; ^**P<0.001 vs vehicle; #P<0.01 vs vehicle and <0.02 vs ET-1. (b) ^*P<0.02 vs vehicle; ^**P<0.001 vs control; ^***P<0.01 vs vehicle; #P<0.001 vs vehicle; ^*#P<0.05 vs ET-1.