Cyclo-oxygenase-2 in vascular smooth muscle.
Two isoforms of cyclo-oxygenase (COX) have been identified; a constitutive isoform (COX-1), found in abundance in platelets and the vascular endothelium, considered important for the roles of prostanoids and a cytokine/mitogen inducible isoform (COX-2), which is thought responsible for the majority of the inflammatory prostanoid production. As a number of COX metabolites regulate vascular smooth muscle cell function and the interaction between the vessel and circulating components, we have discussed the possibility that COX-2 can be induced in, and regulate human arterial or venous smooth muscle cell function. It is now clear that COX-2 can be induced in freshly isolated vessels in culture, which can be further stimulated by addition of pro-inflammatory cytokines. Interestingly, smooth muscle cells derived from saphenous vein can release extremely high levels of prostanoids, and express greater levels of COX-2 protein than internal mammary artery cells. This difference can be accounted for by an arterial cell-specific negative feedback mechanism. In addition to inducing COX-2, certain cytokines regulate smooth muscle function, by regulating cell proliferation, adhesion, and mediator release. The effects of COX-2 activity on these smooth muscle cell responses will be further discussed.
Bishop-Bailey
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Center for Vascular Biology, Department of Physiology, University of Connecticut Health Center, Farmington, CT 06030-3505, USA.
Hla
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Mitchell
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JA
D000818:Animals; D051546:Cyclooxygenase 2; D016207:Cytokines / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins; D009131:Muscle, Smooth, Vascular / Q000201:enzymology* / Q000503:physiopathology; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism*; D014652:Vascular Diseases / Q000201:enzymology / Q000503:physiopathology
D016207:Cytokines; D007527:Isoenzymes; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases