A model with original conditions and materials to test potential inhibitors of cyclooxygenase-2 versus cyclooxygenase-1 in isolated human blood cells.
The inflammatory process can be influenced by an enzyme known as cyclooxygenase, which exists in two isoforms: COX-1, the constitutive form, and COX-2, which is only synthesized in the case of inflammation and has negative side effects. To decrease these undesirable effects, current research seeks to discover compounds that selectively inhibit COX-2 versus COX-1. When added to the samples, arachidonic acid activates the synthesis of COX-2. This explains why the two isoforms proceed in different ways. As for COX-1, human lymphocytes and monocytes were activated with 50 microM of calcium ionophore for 1 h at 37 degrees C with 50 microM of arachidonic acid, and the quantity of thromboxane B(2) (TxB(2)) was measured by radioimmuno-assay (RIA). As for COX-2, cells were first incubated with acetylsalicylic acid to block COX-1, then stimulation of COX-2 was performed using 8 mcg/ml lipopolysaccharide (LPS) for 3 h at 37 degrees C with 50 microM arachidonic acid. The IC(50) values for reference compounds were reproducible, taking into consideration the passage through the plasmatic membrane and the transduction signal, while avoiding the problems of binding with plasma proteins and using identical cells, unlike other models.
Faculté des Sciences Pharmaceutiques et Biologiques, Laboratoire de Pharmacologie, Pharmacocinetique et Pharmacie Cliniques, Lille, France.
X
X
Siomboing
O
O
D'Hondt
M
M
Luyckx
B
B
Gressier
T
T
Dine
C
C
Brunet
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D016718:Arachidonic Acid / Q000494:pharmacology*; D015153:Blotting, Western; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000097:blood; D008070:Lipopolysaccharides / Q000494:pharmacology; D008565:Membrane Proteins; D008954:Models, Biological; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis / Q000097:blood
D000894:Anti-Inflammatory Agents, Non-Steroidal; D007527:Isoenzymes; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D016718:Arachidonic Acid; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases