Within vessels, cyclooxygenase (COX) is expressed constitutively ( @entity9859 ) in endothelial cells where its production of @entity4770 is thought to contribute to the maintenance of vascular integrity. Recently, a novel isoform of COX, @entity2247 , has been described that is induced in animal arterial vessels after physical damage or exposure to proinflammatory cytokines. However, induction of @entity2247 in @entity1 vessels has not been characterized. Moreover, the relative ability of arteries and veins to express @entity2247 has not been addressed. Thus, we have compared the ability of segments of @entity1 saphenous vein and internal mammary artery, obtained from the same @entity1 , to express @entity2247 activity and mRNA after organ culture in the presence and absence of @entity1356 . @entity2247 metabolites, measured by radioimmunoassay, were released by both the internal mammary artery and saphenous vein in the following rank order: @entity1421 > or = @entity4770 thromboxane A2. Inclusion of @entity1356 in the culture medium increased the release of @entity2918 by the saphenous vein but not by the internal mammary artery. However, the selective @entity2247 inhibitor @entity8228 significantly attenuated @entity4770 release from both tissues. Northern blot analysis showed no detectable @entity2247 mRNA in freshly prepared saphenous vein or internal mammary artery. In contrast, after 48 hours in organ culture, low levels of @entity2247 mRNA were detected in both internal mammary artery and saphenous vein, an effect that was greatly increased by @entity1356 . These observations show that @entity2247 is induced in @entity1 saphenous vein and internal mammary artery and suggest that this may occur in @entity1 after coronary artery bypass graft surgery. The induction of @entity2247 and subsequent release of @entity4770 may represent an endogenous defense mechanism against @entity16 incurred during surgical preparation of these vessels for bypass.

Induction of cyclooxygenase-2 in XXXX saphenous vein and internal mammary artery.

@entity1 :: ('9606', 'Species') :: ['humans', 'human', 'patient'] @entity1356 :: ('3553', 'Gene') :: ['interleukin-1 beta'] @entity1421 :: ('MESH:D015232', 'Chemical') :: ['prostaglandin E2'] @entity16 :: ('MESH:D009422', 'Disease') :: ['endothelial damage'] @entity2918 :: ('MESH:D011453', 'Chemical') :: ['prostanoids'] @entity4770 :: ('MESH:D011464', 'Chemical') :: ['prostacyclin'] @entity9859 :: ('4512', 'Gene') :: ['COX-1'] @entity2247 :: ('4513', 'Gene') :: ['COX-2'] @entity8228 :: ('MESH:C080955', 'Chemical') :: ['NS-398']
@entity1 :: (9606,Species) :: ['human']
