Table 2.
cAMP and IP Signaling Properties of PTH and PTHrP Ligands
| cAMP
|
IP
|
|||||
|---|---|---|---|---|---|---|
| HKRK-B64 Cellsa
|
ROS 17/2.8 Cellsb
|
COS-7 Cells (hPTHR)c
|
||||
| EC50 (nm) | Emax (pmol/well) | EC50 (nm) | Emax (pmol/well) | EC50 (nm) | Emax(cpm/well) | |
| [Nle8,21,Tyr34]rPTH(1–34)NH2 | 5.1 ± 0.5 | 55 ± 12 | 0.60 ± 0.1 | 353 ± 54 | 18 ± 3 | 2407 ± 138 |
| [His5,Nle8,21,Tyr34]rPTH(1–34)NH2 | 2.7 ± 0.6g | 59 ± 12 | 2.8 ± 0.2g | 398 ± 68 | 30 ± 12 | 2231 ± 229 |
| [Tyr36]hPTHrP(1–36)NH2 | 5.6 ± 1.3 | 62 ± 15 | 0.78 ± 0.23 | 366 ± 43 | 23 ± 8 | 2514 ± 270 |
| [Ile5,Tyr36]hPTHrP(1–36)NH2 | 5.4 ± 1.9 | 61 ± 14 | 1.0 ± 0.6 | 355 ± 51 | 23 ± 7 | 2793 ± 303 |
a
Data are means (±sem) from four experiments; Emax for basal cAMP (not subtracted) was 5.2 ± 0.9 pmol/well.
b
Data are means (±sem) from three experiments; Emax for basal cAMP (not subtracted) was 21 ± 1 pmol/well.
c
Data are means (±sem) from five experiments; Emax for basal IP value (not subtracted) was 330 ± 8 cpm/well.
d
d P vs. [Nle8,21,Tyr34]rPTH(1–34)NH2 ≤ 0.02.