Table 6. Relative Agonist Potencies of Natural and Synthetic Prostaglandins for PG Receptor Subtypesa.
| agonist
potency (EC50\; nM) at various prostaglandin receptors
and subtypes |
||||||||
|---|---|---|---|---|---|---|---|---|
| compound | DP-receptor (↑ cAMP) | EP1-receptor (↑ PI turnover; or other response) | EP2-receptor (↑ cAMP; or other response | EP3-receptor (↓ cAMP various functional responses) | EP4-receptor (↑ cAMP) | FP-receptor (↑ PI turnover at human cloned FP-receptor; or other responses) | IP-receptor (↑ cAMP or other response) | TP-receptor (↑ PI turnover; or other response) |
| PGD2 | 74 | 3190 | 58 000 | nd | >10 000 | >100; 222 | >10 000 | >10 000 |
| PGI2 | >10 000 | 319 | >10 000 | 3 019 | >10 000 | >5 000 | 7 | >10 000 |
| PGE2 | >1 000 | 2.9 | 67 | 19.9; 45; 4.5 | 40 | >2 500 | 3 310 | >10 000 |
| PGF2α | >10 000 | 29 | >10 000 | 691; 2 000 | >10 000 | 29 ± 2 | 3 000 | >10 000 |
| bimatoprost free acid | >10 000 | 2.7 | >10 000 | nd | >10 000 | 3.3 ± 0.7 | >10 000 | >10 000 |
| travoprost free acid | >10 000 | nd | >10 000 | >10 000 | >10 000 | 2.4 ± 0.3 | >10 000 | >10 000 |
| latanoprost free acid (PHXA85) | >10 000 | 119 | 20 000 | 12 000 | >10 000 | 45.7 ± 8.4 | >10 000 | >10 000 |
| cloprostenol | >10 000 | 93 | >10 000 | 228 | >10 000 | 0.73 ± 0.1 | >10 000 | >10 000 |
| unoprostone (free acid; UF-021) | >10 000 | >30 000 | >10 000 | >10 000 | >10 000 | 3 220 ± 358 | >10 000 | >10 000 |
a
Data are from various sources using different methodologies and functional readouts. Note that the endogenously produced PGs exhibit poor receptor selectivity in isolated cell/tissue preparations. Receptor selectivity by the natural PGs may be achieved at the site of action in vivo depending on the local PG concentration. nd = not determined.158