Figure 16.

Effects of ET-1 (10 nM), oxotremorine (Oxo, 10 μM) and/or pertussis toxin (PTX, 50 ng·mL⁻¹) (A) and/or PD 098059 (PD, at the concentrations given) (B) on [³H]-proline incorporation in MRC-5 human lung fibroblasts; 10⁵ cells were seeded in 12-well dishes. Cells were first cultured for 24 h in presence of 10% FCS, followed by additional 24 h under FCS-free conditions. Thereafter, [³H]-proline (37 kBq) was added alone or in combination with test drugs, and cells were cultured for further 24 h. In the respective experiments, PTX was present 6 h and PD 30 min prior to the exposure to ET-1 or Oxo. Radioactivity incorporated in cellular and extracellular protein was determined and is expressed as % of the mean value of the controls of each cell preparation. Given are means ± SEM of n = 9 experiments. Significance of differences: ***P < 0.001 versus Ctr.; ⁺⁺⁺P < 0.001 versus respective value in presence PTX or ET-1 alone; ^#P < 0.01; ^##P < 0.001 versus respective value in presence of ET-1 alone.