IFNγ Downregulates EP Receptors While Not Affecting kd
| Cells . | ECFC Purity . | kd . | Low-Affinity No. of Receptors . | kd . | High-Affinity No. of Receptors . | ||
|---|---|---|---|---|---|---|---|
| . | (%) . | (nmol/L) . | Per Cell . | Per ECFC . | (nmol/L) . | Per Cell . | Per ECFC . |
| Control | |||||||
| 1 | 36 ± 3 | 0.14 | 255 | 714 | 0.04 | 175 | 512 |
| 2 | 33 ± 2 | 0.28 | 314 | 952 | 0.10 | 179 | 542 |
| 3 | 75 ± 5 | 0.08 | 556 | 741 | 0.04 | 405 | 540 |
| Mean | 48 ± 19 | 0.17 ± 0.08 | 375 ± 130 | 802 ± 106 | 0.06 ± 0.03 | 253 ± 107 | 531 ± 14 |
| IFNγ | |||||||
| 1 | 34 ± 1 | 0.14 | 199 | 559 | 0.05 | 136 | 398 |
| 2 | 34 ± 3 | 0.27 | 233 | 696 | 0.10 | 136 | 406 |
| 3 | 75 ± 6 | 0.09 | 421 | 561 | 0.05 | 320 | 427 |
| Mean | 48 ± 19 | 0.17 ± 0.08 | 284 ± 98 | 605 ± 64 | 0.07 ± 0.02 | 197 ± 87 | 410 ± 12 |
| P value | >.70 | >.50 | .06 | .03 | >.40 | .06 | .003 |
| Cells . | ECFC Purity . | kd . | Low-Affinity No. of Receptors . | kd . | High-Affinity No. of Receptors . | ||
|---|---|---|---|---|---|---|---|
| . | (%) . | (nmol/L) . | Per Cell . | Per ECFC . | (nmol/L) . | Per Cell . | Per ECFC . |
| Control | |||||||
| 1 | 36 ± 3 | 0.14 | 255 | 714 | 0.04 | 175 | 512 |
| 2 | 33 ± 2 | 0.28 | 314 | 952 | 0.10 | 179 | 542 |
| 3 | 75 ± 5 | 0.08 | 556 | 741 | 0.04 | 405 | 540 |
| Mean | 48 ± 19 | 0.17 ± 0.08 | 375 ± 130 | 802 ± 106 | 0.06 ± 0.03 | 253 ± 107 | 531 ± 14 |
| IFNγ | |||||||
| 1 | 34 ± 1 | 0.14 | 199 | 559 | 0.05 | 136 | 398 |
| 2 | 34 ± 3 | 0.27 | 233 | 696 | 0.10 | 136 | 406 |
| 3 | 75 ± 6 | 0.09 | 421 | 561 | 0.05 | 320 | 427 |
| Mean | 48 ± 19 | 0.17 ± 0.08 | 284 ± 98 | 605 ± 64 | 0.07 ± 0.02 | 197 ± 87 | 410 ± 12 |
| P value | >.70 | >.50 | .06 | .03 | >.40 | .06 | .003 |
Day-5 ECFCs were cultured as described in Table 1. The cells were then incubated with increasing concentrations of 125I-rhEP (0 to 0.8 nmol/L) for 48 hours at 0°C, and specific binding was determined. The kd and number of receptors were calculated by Scatchard analysis.