TABLE 1.
Agonist potencies (EC50) and maximal responses (Rmax) for calcitonin secretion, IP1 accumulation and intracellular calcium response in 6-23 cells.
Potencies are in μM for all assays. Rmax levels are in pg/ml for the calcitonin assay and nM for the IP1 assay and have been normalized to Δfluorescence units of 10 mM [Ca2+]e in the intracellular calcium assay.
| Assay | [Ca2+]e |
[Sr2+]e |
||
|---|---|---|---|---|
| Rmax ± S.E.M. | EC50 (pEC50± S.E.M.) | Rmax ± S.E.M. | EC50 (pEC50 ± S.E.M.) | |
| Calcitonin | 313 ± 20 | 2440 (2.61 ± 0.13) | 304 ± 24 | 794 (3.10 ± 0.13) |
| IP1 | 858 ± 150 | 4810 (2.32 ± 0.01) | 787 ± 46 | 8320 (2.08 ± 0.01) |
| Intracellular calcium | 100 ± 3.50 | 1470 (2.83 ± 0.09) | 44.3 ± 1.18 | 3050 (2.52 ± 0.05) |