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Potent thromboxane-mediated in vitro bronchoconstrictor effect of endothelin in the guinea-pig
European Journal of Pharmacology,, 178 (1990) 141-142
141
Elsevier EJP 0243R
Rapid communication
Potent thromboxane-mediated in vitro bronchoconst of endothe||n in the guinea-pig
ctor effect
Bruno Battistini, Janos Filep and Pierre Siro~s Department of Pharmacology, Facultyof Medicine, Universityof Sherbrooke, Sherbrooke, Quebec, CanadaJl H 5N4 Received 15 February 1990, accepted 16 February 1990
Endothelin (ET) is a novel peptide isolated from cultured endothelial cells (Yanagisawa et al, 1988). ET has been shown to contract both vascular (Yanagisawa et al., 1988) and non-vascular smooth muscle cells, including guinea pig tracheal strips (Uchida et al., 1988). Recently, indomethacin was found to inhibit the bronchoconstrictor action of ET in vivo (Payne and Whittle, 1988), suggesting that this effect of ET is mediated through the release of cyclo-oxygenase products of arachidonic acid metabolism. We now report that this metabolite may be thromboxane A 2Male Dunkin Hartley guinea pigs weighing 450-600 g were killed by cervical dislocation. Trachea and external bronchi were quickly removed and placed in 5-ml organ baths. The tissues were equilibrated with oxygenated (95~o O2-5% CO2) Krebs-Henseleit solution under an initial tension of 1.5 g for 1 h. Synthetic ET (endothelin-1, Peninsula Labs, Belmont, CA) was added cumulatively to tissues pretrcated with BM 13177 (10-50 pM, 4-(2-(benzenesulphonamido)-ethyl)phenoxyacetic acid, Boehringer-Mannheim, FRG), a specific thromboxane A2 receptor antagonist (Stegmeier et al., 1984) or its vehicle for 10 rain. The responses were recorded on a Grass 7D polygraph using Grass FT 03C isometric transducers.
Correspondence to: Janos Filep, Department of Pharmacology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, Quebec, Canada J1H 5N4.
Under control conditions, ET (1-100 nM) caused a dose-dependent contraction of both trachea and external bronchi (fig. 1). The contraction developed more slowly and lasted longer than that evoked by histamine. On a molar basis, ET appeared to be about 40 times more potent than histamine. Pretreatment of the tissues with BM 13177 significantly abolished the constrictor effect of ET over the dose range studied (fig. 1). BM 13177 (50 /zM) did not modify the response to histamine (104.3 + 4.7 and 107.5 + 3.5~o of control contractions evoked by 0.9 and 2.7 pM of histamine in the presence of the antagonist, respectively, n = 7, P > 0.05). Similar results were obtained with another thromboxane receptor antagonist, BM 13505 (4-[2-(4-chlorobenzene sulphonylamino)-ethyl] benzene acetic acid) (data not shown). The present data both confirm that ET is a potent constrictor of the guinea pig an'ways and suggest that this action of ET is mediated at least in part by the release of thromboxane A2, a well known bronchoconstrictor. This conclusion is further supported by the finding that ET can release thromboxane A 2 from isolated, perfused guinea pig lungs (De Nucci et al., 1988). Since BM 13177 at 50 #M did not exert any effect on the fo_rmation of various eicosanoids (Stegmeier et al., 1984), and did not inhibit the effects of serotonin, platelet-activating factor (Stegrneier et al., 1984) and histamine (present study), its effect can probably be attributed to antagonism of thromboxane receptors. Whether ET can release other eicosanoids
0014-2999/90/$03.50 © 1990 Elsevier Science Publishers B.V. (Biomedical Division)
~CH|
and whether its bronchoconstrictor effect is mediated by thromboxane in other species, remains to be investigated.
l
Ac~no~~nts BM 13177 was a generous gift from Dr. K. Stegmeier (Mannheim, FRG). The authors thank the Medical Research Council of Canada for financial support and Ms. Carmen Labrecque for secretarial assistance. J.F. and P.S. are in receipt of Medical Research Council Fellowships and Scientist Award respectively.
0, 9
8 g N a O l l m l J ~ i- leg U l
7
References TRACHEA O Ceatrea
m
O' ~ - - - - 9
I~'-"~ T 8 ENDO~IEI,IN |-Iel M|
. ?
Fig. 1. |ahibition by BM 13177 of endothelin-induced contraction ot" guinea pig trachea and external bronchi in vitro. The resuits are expressed as a percentage of the maximal response to 4.5 ~M of histamine and are means + S.E.M. of 3-5 independem expedmems. * P < 0.05 (Mann-Whitney U-test) was taken s ~ c c ~ t for ~ dif~eren~ fr,.~n~~.~ec~at~o~.
De Nucci, G., R. Thomas, P. D'Orleans-Juste, E. Antunes, C. Wadder, T.D. Warner and J.R. Vane, 1988, Pressor effects of circulating endothelin are limited by its removal in the pulmonary circulation and by the release of prostacycfin and endothefium-derived relaxing factor, Proc. Natl. Acad. Sci. U.S.A. 85, 9797. Payne, A.N. and B.J.R. Whittle, 1988, Potent cyclooxygenase-mediated broncboconstrictor effects of endothelin in the guinea pig in vivo, European J. Pharmacol. 158, 3O3. Stegmeier, K., J. Pill, B. Miiller-Beckmann, F.H. Schmidt, E.C. Witte, H.P. Wolff and H. Patscheke, 1984, The pharmacological profile of the thromboxane A 2 antagonist BM 13.177, a new anti-platelet and anti-thrombotic drug, Thromb. Res. 35, 379. Uchida, Y., H. Ninomiya, M., Saotome, A. Nomura, M. Ohtsuka, M. Yanagisawa, K. Goto, T. Masaki and S. Hasegawa, 1988, European J. Pharmacol. 154, 227. Yanagisawa, M., H. Kurihara, S. Kimura, Y. Tomobe, M. KobayashL Y. Mitsui, Y. Yazaki, K. Goto and T. Masaki, 1988, A novel potent vasoconstrictor peptide produced by vascular endothelial cells, Nature 332, 411.
141
Elsevier EJP 0243R
Rapid communication
Potent thromboxane-mediated in vitro bronchoconst of endothe||n in the guinea-pig
ctor effect
Bruno Battistini, Janos Filep and Pierre Siro~s Department of Pharmacology, Facultyof Medicine, Universityof Sherbrooke, Sherbrooke, Quebec, CanadaJl H 5N4 Received 15 February 1990, accepted 16 February 1990
Endothelin (ET) is a novel peptide isolated from cultured endothelial cells (Yanagisawa et al, 1988). ET has been shown to contract both vascular (Yanagisawa et al., 1988) and non-vascular smooth muscle cells, including guinea pig tracheal strips (Uchida et al., 1988). Recently, indomethacin was found to inhibit the bronchoconstrictor action of ET in vivo (Payne and Whittle, 1988), suggesting that this effect of ET is mediated through the release of cyclo-oxygenase products of arachidonic acid metabolism. We now report that this metabolite may be thromboxane A 2Male Dunkin Hartley guinea pigs weighing 450-600 g were killed by cervical dislocation. Trachea and external bronchi were quickly removed and placed in 5-ml organ baths. The tissues were equilibrated with oxygenated (95~o O2-5% CO2) Krebs-Henseleit solution under an initial tension of 1.5 g for 1 h. Synthetic ET (endothelin-1, Peninsula Labs, Belmont, CA) was added cumulatively to tissues pretrcated with BM 13177 (10-50 pM, 4-(2-(benzenesulphonamido)-ethyl)phenoxyacetic acid, Boehringer-Mannheim, FRG), a specific thromboxane A2 receptor antagonist (Stegmeier et al., 1984) or its vehicle for 10 rain. The responses were recorded on a Grass 7D polygraph using Grass FT 03C isometric transducers.
Correspondence to: Janos Filep, Department of Pharmacology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, Quebec, Canada J1H 5N4.
Under control conditions, ET (1-100 nM) caused a dose-dependent contraction of both trachea and external bronchi (fig. 1). The contraction developed more slowly and lasted longer than that evoked by histamine. On a molar basis, ET appeared to be about 40 times more potent than histamine. Pretreatment of the tissues with BM 13177 significantly abolished the constrictor effect of ET over the dose range studied (fig. 1). BM 13177 (50 /zM) did not modify the response to histamine (104.3 + 4.7 and 107.5 + 3.5~o of control contractions evoked by 0.9 and 2.7 pM of histamine in the presence of the antagonist, respectively, n = 7, P > 0.05). Similar results were obtained with another thromboxane receptor antagonist, BM 13505 (4-[2-(4-chlorobenzene sulphonylamino)-ethyl] benzene acetic acid) (data not shown). The present data both confirm that ET is a potent constrictor of the guinea pig an'ways and suggest that this action of ET is mediated at least in part by the release of thromboxane A2, a well known bronchoconstrictor. This conclusion is further supported by the finding that ET can release thromboxane A 2 from isolated, perfused guinea pig lungs (De Nucci et al., 1988). Since BM 13177 at 50 #M did not exert any effect on the fo_rmation of various eicosanoids (Stegmeier et al., 1984), and did not inhibit the effects of serotonin, platelet-activating factor (Stegrneier et al., 1984) and histamine (present study), its effect can probably be attributed to antagonism of thromboxane receptors. Whether ET can release other eicosanoids
0014-2999/90/$03.50 © 1990 Elsevier Science Publishers B.V. (Biomedical Division)
~CH|
and whether its bronchoconstrictor effect is mediated by thromboxane in other species, remains to be investigated.
l
Ac~no~~nts BM 13177 was a generous gift from Dr. K. Stegmeier (Mannheim, FRG). The authors thank the Medical Research Council of Canada for financial support and Ms. Carmen Labrecque for secretarial assistance. J.F. and P.S. are in receipt of Medical Research Council Fellowships and Scientist Award respectively.
0, 9
8 g N a O l l m l J ~ i- leg U l
7
References TRACHEA O Ceatrea
m
O' ~ - - - - 9
I~'-"~ T 8 ENDO~IEI,IN |-Iel M|
. ?
Fig. 1. |ahibition by BM 13177 of endothelin-induced contraction ot" guinea pig trachea and external bronchi in vitro. The resuits are expressed as a percentage of the maximal response to 4.5 ~M of histamine and are means + S.E.M. of 3-5 independem expedmems. * P < 0.05 (Mann-Whitney U-test) was taken s ~ c c ~ t for ~ dif~eren~ fr,.~n~~.~ec~at~o~.
De Nucci, G., R. Thomas, P. D'Orleans-Juste, E. Antunes, C. Wadder, T.D. Warner and J.R. Vane, 1988, Pressor effects of circulating endothelin are limited by its removal in the pulmonary circulation and by the release of prostacycfin and endothefium-derived relaxing factor, Proc. Natl. Acad. Sci. U.S.A. 85, 9797. Payne, A.N. and B.J.R. Whittle, 1988, Potent cyclooxygenase-mediated broncboconstrictor effects of endothelin in the guinea pig in vivo, European J. Pharmacol. 158, 3O3. Stegmeier, K., J. Pill, B. Miiller-Beckmann, F.H. Schmidt, E.C. Witte, H.P. Wolff and H. Patscheke, 1984, The pharmacological profile of the thromboxane A 2 antagonist BM 13.177, a new anti-platelet and anti-thrombotic drug, Thromb. Res. 35, 379. Uchida, Y., H. Ninomiya, M., Saotome, A. Nomura, M. Ohtsuka, M. Yanagisawa, K. Goto, T. Masaki and S. Hasegawa, 1988, European J. Pharmacol. 154, 227. Yanagisawa, M., H. Kurihara, S. Kimura, Y. Tomobe, M. KobayashL Y. Mitsui, Y. Yazaki, K. Goto and T. Masaki, 1988, A novel potent vasoconstrictor peptide produced by vascular endothelial cells, Nature 332, 411.