Cloned human EP1 prostanoid receptor pharmacology characterized using radioligand binding techniques.

Article Details

Citation

Copy to clipboard

Sharif NA, Davis TL

Cloned human EP1 prostanoid receptor pharmacology characterized using radioligand binding techniques.

J Pharm Pharmacol. 2002 Apr;54(4):539-47.

PubMed ID

11999132 [ View in PubMed

]

Abstract

Prostaglandins such as prostaglandin E2 (PGE2) interact with EP-class prostanoid receptors including EP1, EP2, EP3 and EP4 subtypes. We have conducted a detailed pharmacological characterization of the binding of [3H]-PGE2 to recombinant human EP1 prostanoid receptors expressed in human embryonic kidney (HEK-293) cells using a broad panel of natural and synthetic prostanoids. The receptor displayed high affinity (Kd = 16.0 +/- 0.69 nM; n = 3) for [3H]-PGE2, and was expressed at high levels (Bmax =3.69 +/- 0.30 pmol (mg protein)(-1)) in cell membranes of HEK-293 cells. Specific binding constituted 97.5 +/- 1.4% (n = 12) of the total binding. In competition assays, the rank order of affinities of natural prostanoids for the receptor was PGE2 > PGE1 > PGF2 > PGI2 > PGD2. PGE2 was more effective than PGE1 at displacing bound [3H]-PGE2 (Ki for PGE2 = 14.9 +/- 2.2 nM; Ki for PGE1 = 165 +/- 29 nM). The affinities of enprostil (Ki = 14.5 +/- 3.1 nM) and 17-phenyl-omega-trinor-PGE2 (Ki = 7.3 +/- 2.7 nM) for the receptor were quite similar to that of PGE2, while that of sulprostone (Ki = 137 + 13 nM) more closely resembled PGE1. Some compounds historically classified as specific for DP prostanoid receptors bound with relatively high affinity to the recombinant human EP1 receptor (e.g. ZK118182 (K = 73.4 +/- 8.6 nM) and ZK110841 (K = 166 +/- 20 nM)). All FP (e.g. travoprost acid, fluprostenol), IP (iloprost) and TP (SQ29548) receptor-specific ligands exhibited low affinity (Ki > or = 1 microM).

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Iloprost	Prostaglandin E2 receptor EP1 subtype	Protein	Humans	Yes	Agonist	Details