title: Differential reactivity of human mammary artery and saphenous vein to prostaglandin E(2) : implication for cardiovascular grafts.
abstract: OBJECTIVE
  Human internal mammary arteries (IMA) and saphenous veins (SV) are frequently used for coronary artery bypass graft surgery. Intra- and postoperatively, the bypass grafts are exposed to inflammatory conditions, under which there is a striking increase in the synthesis of prostaglandin E(2) (PGE(2) ). In this context, the physiological response of these vascular grafts to PGE(2) is highly relevant. The aim of this study was thus to characterize the PGE(2) receptor subtypes (EP(1) , EP(2) , EP(3) or EP(4) ) involved in modulation of the vascular tone in these two vessels.
  
  
  METHODS
  Rings of IMA and SV were prepared from 48 patients. The rings were mounted in organ baths for isometric recording of tension, and a pharmacological study was performed, together with associated reverse transcriptase PCR and immunohistochemistry experiments.
  
  
  RESULTS
  PGE(2) induced contractions of IMA (E(max) = 1.43 ± 0.20 g; pEC(50) = 7.50 ± 0.10); contractions were also observed with the EP(3) receptor agonists, sulprostone, 17-phenyl-PGE(2) , misoprostol or ONO-AE-248. In contrast, PGE(2) induced relaxation of the precontracted SV (E(max) =-0.22 ± 0.02 g; pEC(50) = 7.14 ± 0.09), as did the EP(4) receptor agonist, ONO-AE1-329. These results were confirmed by the use of selective EP receptor antagonists (GW627368X, L-826266, ONO-8713, SC-51322) and by molecular biology and immunostaining.
  
  
  CONCLUSIONS
  PGE(2) induced potent and opposite effects on the human vascular segments used for grafting, namely vasoconstriction of the IMA and vasodilatation of the SV via EP(3) and EP(4) receptors respectively. These observations suggest that EP(3) and EP(4) receptors could constitute therapeutic targets to increase vascular graft patency.
authors.affiliation: INSERM, CHU X. Bichat, Paris, France.
authors.forename: N
authors.initials: N
authors.lastname: Foudi
authors.forename: L
authors.initials: L
authors.lastname: Kotelevets
authors.forename: I
authors.initials: I
authors.lastname: Gomez
authors.forename: L
authors.initials: L
authors.lastname: Louedec
authors.forename: D
authors.initials: D
authors.lastname: Longrois
authors.forename: E
authors.initials: E
authors.lastname: Chastre
authors.forename: X
authors.initials: X
authors.lastname: Norel
mesh_terms: D000178:Acrylamides / Q000494:pharmacology; D000368:Aged; D001026:Coronary Artery Bypass / Q000379:methods; D015232:Dinoprostone / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D005260:Female; D006801:Humans; D054833:Isoindoles / Q000494:pharmacology; D008297:Male; D008323:Mammary Arteries / Q000187:drug effects* / Q000378:metabolism / Q000637:transplantation*; D008738:Methyl Ethers / Q000494:pharmacology; D016595:Misoprostol / Q000494:pharmacology; D009281:Naphthalenes / Q000494:pharmacology; D018078:Receptors, Prostaglandin E / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism; D012501:Saphenous Vein / Q000187:drug effects* / Q000378:metabolism / Q000637:transplantation*; D013449:Sulfonamides / Q000494:pharmacology; D058017:Vascular Grafting / Q000379:methods
chemical_list: D000178:Acrylamides; D054833:Isoindoles; C508710:L-826266; D008738:Methyl Ethers; C515270:N-(2-(4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo(f)isoindol-2-yl)phenyl)acetyl)benzene sulphonamide; D009281:Naphthalenes; C121546:ONO AE 248; C461399:ONO-AE1-329; D018078:Receptors, Prostaglandin E; D013449:Sulfonamides; D016595:Misoprostol; C016767:sulprostone; D015232:Dinoprostone