pH dependency of agonist-stimulated adenylyl cyclase activity in human erythroid progenitor cells
| Agonist | [pH]i | ||
|---|---|---|---|
| 6.9 | 7.26 | 7.7 | |
| cAMP formation in multiples of basal activity | |||
| PGE1(10 μm) | 3.01 ± 0.37 (9) | 5.66 ± 1.10 (10) | 7.44 ± 1.56 (12) |
| PGE1/thrombin (10 μm/2 units/ml) | 7.36 ± 0.93 (11) | 14.53 ± 2.14 (11) | 18.10 ± 3.39 (10) |
| PGE1/PMA(10 μm/10 nm) | 4.45 ± 0.71 (6) | 8.04 ± 1.23 (6) | 11.03 ± 2.21 (6) |
| Forskolin(25 μm) | 1.64 ± 0.16 (6) | 2.95 ± 0.38 (6) | 4.69 ± 0.78 (6) |
Progenitor cells were equilibrated with the indicated pH values in the presence of 10 μm nigericin at 36° in KCl medium. Stimulation was for 11 min with the listed agonists. The numbers give fold stimulation over basal. Basal cAMP formation was similar at all pH values tested. Note that the relative amplification of the PGE1-induced cAMP signal by thrombin or PMA remained constant within the pH range tested.
Values are mean ± standard error.