title: Human internal mammary artery contraction by isoprostaglandin f(2alpha) type-III [8-iso-prostaglandin F(2alpha)].
abstract: Isoprostaglandin F(2alpha) type-III (formerly known as 8-iso-prostaglandin F(2alpha)) is produced in large quantities in vivo in clinical situations associated with oxidant stress such as atherosclerosis, hypercholesterolemia, and myocardial reperfusion. Isoprostaglandin F(2alpha) type-III may alter smooth muscle and platelet functions. The aim of this study was to evaluate the effects of isoprostaglandin F(2alpha) type-III on isolated human internal mammary arteries, and to characterise the signalling underlying mechanisms. In organ baths, concentration-dependent contractions of human internal mammary arteries were obtained in response to isoprostaglandin F(2alpha) type-III stimulation. The responses to isoprostaglandin F(2alpha) type-III were inhibited in a concentration-dependent manner by the thromboxane A(2) receptor antagonist, GR 32191 ([1R-[1 alpha(Z), 2beta,3beta,5 alpha(+)-7-[[1, 1'-biphenyl)-4-yl]methoxy]-3-hydroxy-2-(1-piperidinyl) cyclo pentyl]-4-4heptanoic acid], hydrochloride), 3x10(-9) to 3x10(-7) M). However, this effect was associated with a decreased maximal contraction. AH 6809 (6-isopropoxy-9-oxoxanthene-2-carboxylic acid, 10(-6) to 3x10(-5) M), an EP(1)-DP receptor antagonist had no effect on isoprostaglandin F(2alpha) type-III-induced contractions. The maximal responses to isoprostaglandin F(2alpha) type-III were significantly reduced in the presence of the cyclooxygenase inhibitor indomethacin (10(-5) M) (E(max): 147+/-20% vs. 213+/-19% in control group, P<0.05). Isoprostaglandin F(2alpha) type-III stimulated thromboxane B(2) release (5.7-fold increase) from human internal mammary arteries. Baicaleine, a non-specific lipoxygenase inhibitor, (10(-4) M) and AA 861 (2,3,5-trimethyl-6-(12-hydroxy-5, 10-dodecadiynyl)-1,4 benzoquinone), a 5-lipoxygenase inhibitor (10(-5) M) did not affect isoprostaglandin F(2alpha) type-III response. In conclusion, this study shows that (1) isoprostaglandin F(2alpha) type-III is a vasoconstrictor in human internal mammary arteries, with a potency equivalent to prostaglandin F(2alpha), (2) the contractions induced by isoprostaglandin F(2alpha) type-III are mediated by TP receptor but not EP(1)-DP-receptor activation, (3) thromboxane A(2) but not cysteinyl leukotrienes production is involved in the vascular effects of isoprostaglandin F(2alpha) type-III. Isoprostaglandin F(2alpha) type-III, produced at sites of free radical generation, may play an important role in internal mammary artery spasm in situations of oxidant stress such as coronary bypass surgery.
authors.affiliation: Laboratory of Pharmacology, LSCPA EA2937, Faculté de Médecine de Grenoble, F-38706 Cedex, La Tronche, France. jean-luc.cracowski@ujf-grenoble.fr
authors.forename: J L
authors.initials: JL
authors.lastname: Cracowski
authors.forename: F
authors.initials: F
authors.lastname: Stanke-Labesque
authors.forename: P
authors.initials: P
authors.lastname: Devillier
authors.forename: O
authors.initials: O
authors.lastname: Chavanon
authors.forename: M
authors.initials: M
authors.lastname: Hunt
authors.forename: C
authors.initials: C
authors.lastname: Souvignet
authors.forename: G
authors.initials: G
authors.lastname: Bessard
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D000328:Adult; D000368:Aged; D016227:Benzoquinones / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000494:pharmacology; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D028441:F2-Isoprostanes; D005260:Female; D044950:Flavanones; D005419:Flavonoids / Q000494:pharmacology; D006538:Heptanoic Acids / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D015289:Leukotrienes / Q000378:metabolism; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology; D008297:Male; D008323:Mammary Arteries / Q000187:drug effects* / Q000502:physiology; D008875:Middle Aged; D011448:Prostaglandin Antagonists / Q000494:pharmacology; D018078:Receptors, Prostaglandin E / Q000037:antagonists & inhibitors; D058306:Receptors, Prostaglandin E, EP1 Subtype; D017482:Receptors, Thromboxane / Q000037:antagonists & inhibitors; D013929:Thromboxane B2 / Q000378:metabolism; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014966:Xanthenes / Q000494:pharmacology; D044004:Xanthones
chemical_list: D016227:Benzoquinones; D001713:Biphenyl Compounds; D028441:F2-Isoprostanes; D044950:Flavanones; D005419:Flavonoids; D006538:Heptanoic Acids; D015289:Leukotrienes; D016859:Lipoxygenase Inhibitors; C545635:PTGER1 protein, human; D011448:Prostaglandin Antagonists; D018078:Receptors, Prostaglandin E; D058306:Receptors, Prostaglandin E, EP1 Subtype; D017482:Receptors, Thromboxane; D014662:Vasoconstrictor Agents; D014966:Xanthenes; D044004:Xanthones; C075750:8-epi-prostaglandin F2alpha; C053876:6-isopropoxy-9-oxoxanthene-2-carboxylic acid; C006680:baicalein; D013929:Thromboxane B2; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; C036837:2,3,5-trimethyl-6-(12-hydroxy-5,10-dodecadiynyl)-1,4-benzoquinone; D015237:Dinoprost; C060013:vapiprost