Effect of ATP, Adenosine, and 2-Methylthio-ATP on Cellular cAMP Content
| Agonist . | cAMP Content (fmol/cm2) . | |
|---|---|---|
| Without IBMX . | With IBMX (100 μmol/L) . | |
| Control | 123 ± 21 | 203 ± 40 |
| ATP (100 μmol/L) | 247 ± 61* | 385 ± 57* |
| Adenosine (100 μmol/L) | 221 ± 28* | 378 ± 54* |
| 2-Methylthio-ATP (100 μmol/L) | 162 ± 19 | 228 ± 31 |
| 2-Methylthio-ATP (100 μmol/L + adenosine (100 μmol/L) | 281 ± 23* | 440 ± 59* |
| Thrombin (1 U/mL) | 175 ± 26 | 280 ± 42* |
| Epinephrine (1 μmol/L) | — | 348 ± 37* |
| Forskolin (10 μmol/L) | — | 885 ± 113* |
| Agonist . | cAMP Content (fmol/cm2) . | |
|---|---|---|
| Without IBMX . | With IBMX (100 μmol/L) . | |
| Control | 123 ± 21 | 203 ± 40 |
| ATP (100 μmol/L) | 247 ± 61* | 385 ± 57* |
| Adenosine (100 μmol/L) | 221 ± 28* | 378 ± 54* |
| 2-Methylthio-ATP (100 μmol/L) | 162 ± 19 | 228 ± 31 |
| 2-Methylthio-ATP (100 μmol/L + adenosine (100 μmol/L) | 281 ± 23* | 440 ± 59* |
| Thrombin (1 U/mL) | 175 ± 26 | 280 ± 42* |
| Epinephrine (1 μmol/L) | — | 348 ± 37* |
| Forskolin (10 μmol/L) | — | 885 ± 113* |
HUVECs grown on culture dishes (35 mm) were handled in the same way as in the secretion studies. Incubations were performed for 30 minutes at 37°C in the presence of agonists as indicated. cAMP was extracted in 70% ethanol and measured by radioimmunoassay. Results are expressed as the mean ± SEM of 4 individual experiments. vWF release was always measured in the supernatant, with results entirely consistent with the data in Figs 1 and 3.
P < .05 versus corresponding control.