Receptor affinity of peptidic agonists (GnRH and triptorelin), peptidic antagonist (ganirelix), and nonpeptidic antagonists (TAK-013 and FD-1) Ki represents displacement of specific 125I-triptorelin binding from human gonadotropin-releasing hormone receptors stably expressed in CHO cell membranes. Values are means (± S.E.M.) of at least three separate assays performed in duplicate.
Compound | Ki |
|---|---|
| nM | |
| GnRHa | 1.2 ± 0.1 |
| Triptorelin | 0.42 ± 0.07 |
| Ganirelix | 3.8 ± 0.4 |
| TAK-013 | 1.9 ± 0.7 |
| FD-1 | 4.9 ± 1 |
↵ a According to computer analysis of the binding curve of GnRH, a two-site competition model of higher (H) and lower (L) affinity was statistically preferred with KH = 0.54 ± 0.004 nM, KL = 21 ± 10 nM, and RH = 69 ± 3%.