Binding Affinity Profiles of SS-28, SS-14, and [DTPA]SS-14 for Human sst1–5 Receptors
| Compound | Displacement of binding of [125I-LTT]SS-28 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| sst1 | sst2 | sst3 | sst4 | sst5 | |||||
| SS-28 | 2.5 ± 0.3 | 2.1 ± 0.3 | 2.5 ± 0.2 | 2.2 ± 0.3 | 2.1 ± 0.4 | ||||
| SS-14 | 2.1 ± 0.4 | 0.6 ± 0.1 | 3.9 ± 1.3 | 1.9 ± 0.6 | 11.0 ± 3.5 | ||||
| [DTPA]SS-14 | 35 ± 1.6 | 3.9 ± 0.8 | 7.5 ± 1.3 | 5.5 ± 1.1 | 16.0 ± 2.0 | ||||
| [DTPA]octreotide* | >10,000 | 12 ± 2 | 376 ± 84 | >1,000 | 299 ± 50 | ||||
↵* Data are from (20).
Values are mean ± SEM of 3 experiments and represent IC50 values (in nmol/L) of displacement of binding of [125I-Leu8,d-Trp22,Tyr25]SS-28 to cryostat sections of membrane pellets of cells stably expressing sst1 or sst5 (CHO-K1) and sst2, sst3, and sst4 (CCL39 cells), as described in detail previously (20).