Table 1

pK_ivalues for displacement of [³H]PGE₂ by PGE₂ and PGE₂ethanolamide from cell membranes transfected with EP₁, EP₂, EP₃, and EP₄ receptors (n= 3–8)

Compound	hEP₁	hEP₂	hEP₃	hEP₄
PGE₂	8.31 ± 0.16	9.03 ± 0.04	9.34 ± 0.06	9.10 ± 0.04
PGE₂ethanolamide	5.61 ± 0.10	6.33 ± 0.01	6.70 ± 0.13	6.29 ± 0.06