Table 2.
In vitro activity of nuclear PLD and PI-PLC activities in response to either IGF-I or DMSO
| Stimulus | PLD activity | PI-PLC activity |
|---|---|---|
| None | 0.501 ± 0.061 | 18.5 ± 2.4 |
| IGF-I 10 min | 0.487 ± 0.059 | 44.4 ± 5.5 |
| IGF-I 20 min | 0.521 ± 0.065 | 43.1 ± 5.8 |
| IGF-I 30 min | 0.565 ± 0.071 | 42.4 ± 4.7 |
| DMSO 10 min | 1.23 ± 0.15 | 18.2 ± 2.1 |
| DMSO 20 min | 1.97 ± 0.22 | 19.5 ± 2.8 |
| DMSO 30 min | 1.75 ± 0.20 | 18.7 ± 1.9 |
HL-60 cells were exposed to either IGF-I or DMSO for the indicated times. For PLD the data are expressed as the percentage of labeled nuclear phosphatidylethanol relative to total nuclear lipid radioactivity, whereas for PI-PLC they are expressed as nanomoles of radiolabeled inositol (1,4,5) triphosphate per milligram of nuclear protein. The data are the mean of three different experiments ± SD.