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Semiz AT, Teker AB, Yapar K, Doğan BSU, Takır S. Hydrogen sulfide dilates the isolated retinal artery mainly via the activation of myosin phosphatase. Life Sci 2020; 255:117834. [PMID: 32454158 DOI: 10.1016/j.lfs.2020.117834] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/12/2020] [Accepted: 05/19/2020] [Indexed: 02/08/2023]
Abstract
AIMS Hydrogen sulfide (H2S) is shown in ocular tissues and suggested to involve in the regulation of retinal circulation. However, the mechanism of H2S-induced relaxation on retinal artery is not clarified yet. Herein, we aimed to evaluate the role of several calcium (Ca2+) signaling and Ca2+ sensitization mechanisms in the relaxing effect of H2S donor, NaHS, on retinal arteries. MATERIALS AND METHODS Relaxing effects of NaHS (10-5-3 × 10-3M) were determined on precontracted retinal arteries in Ca2+ free medium as well as in the presence of the inhibitors of Ca2+ signaling and Ca2+ sensitization mechanisms. Additively, Ca2+ sensitivity of the contractile apparatus were evaluated by CaCl2-induced contractions in the presence of NaHS (3 × 10-3M). Functional experiments were furtherly assessed by protein and/or mRNA expressions, as appropriate. KEY FINDINGS The relaxations to NaHS were preserved in Ca2+ free medium while NaHS pretreatment decreased the responsiveness to CaCl2. The inhibitors of plasmalemmal Ca2+-ATPase, sarcoplasmic-endoplasmic reticulum Ca2+-ATPase, Na+-Ca2+ ion-exchanger and myosin light chain kinase (MLCK) unchanged the relaxations to NaHS. Likewise, Ca2+ sensitization mechanisms including, rho kinase, protein kinase C and tyrosine kinase were unlikely to mediate the relaxation to NaHS in retinal artery. Whereas, a marked reduction was determined in NaHS-induced relaxations in the presence of MLCP inhibitor, calyculin A. Supportively, NaHS pretreatment significantly reduced phosphorylation of MYPT1-subunit of MLCP. SIGNIFICANCE The relaxing effect of NaHS in retinal artery is likely to be related to the activation of MLCP and partly, to decrement in Ca2+ sensitivity of contractile apparatus.
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Affiliation(s)
- Ayça Toprak Semiz
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, Istanbul 34116, Turkey; Istanbul University, Graduate School of Health Sciences, Istanbul, Turkey
| | - Ayşegül Başak Teker
- Department of Medical Genetics, Faculty of Medicine, Giresun University, Giresun 28200, Turkey
| | - Kürşad Yapar
- Department of Medical Pharmacology, Faculty of Medicine, Giresun University, Giresun 28200, Turkey
| | | | - Selçuk Takır
- Department of Medical Pharmacology, Faculty of Medicine, Giresun University, Giresun 28200, Turkey.
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AlSuleimani YM, Hiley CR. The GPR55 agonist lysophosphatidylinositol relaxes rat mesenteric resistance artery and induces Ca(2+) release in rat mesenteric artery endothelial cells. Br J Pharmacol 2015; 172:3043-57. [PMID: 25652040 DOI: 10.1111/bph.13107] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 01/11/2015] [Accepted: 02/02/2015] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Lysophosphatidylinositol (LPI), a lipid signalling molecule, activates GPR55 and elevates intracellular Ca(2+). Here, we examine the actions of LPI in the rat resistance mesenteric artery and Ca(2+) responses in endothelial cells isolated from the artery. EXPERIMENTAL APPROACH Vascular responses were studied using wire myographs. Single-cell fluorescence imaging was performed using a MetaFluor system. Hypotensive effects of LPI were assessed using a Biopac system. KEY RESULTS In isolated arteries, LPI-induced vasorelaxation was concentration- and endothelium-dependent and inhibited by CID 16020046, a GPR55 antagonist. The CB1 receptor antagonist AM 251 had no effect, whereas rimonabant and O-1918 significantly potentiated LPI responses. Vasorelaxation was reduced by charybdotoxin and iberiotoxin, alone or combined. LPI decreased systemic arterial pressure. GPR55 is expressed in rat mesenteric artery. LPI caused biphasic elevations of endothelial cell intracellular Ca(2+). Pretreatment with thapsigargin or 2-aminoethoxydiphenyl borate abolished both phases. The PLC inhibitor U73122 attenuated the initial phase and enhanced the second phase, whereas the Rho-associated kinase inhibitor Y-27632 abolished the late phase but not the early phase. CONCLUSIONS AND IMPLICATIONS LPI is an endothelium-dependent vasodilator in the rat small mesenteric artery and a hypotensive agent. The vascular response involves activation of Ca(2+)-sensitive K(+) channels and is not mediated by CB1 receptors, but unexpectedly enhanced by antagonists of the 'endothelial anandamide' receptor. In endothelial cells, LPI utilizes PLC-IP3 and perhaps ROCK-RhoA pathways to elevate intracellular Ca(2+). Overall, these findings support an endothelial site of action for LPI and suggest a possible role for GPR55 in vasculature.
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Affiliation(s)
- Y M AlSuleimani
- Department of Pharmacology, University of Cambridge, Cambridge, UK.,Department of Pharmacology and Clinical Pharmacy, College of Medicine and Health Sciences, Sultan Qaboos University, Alkoudh, Sultanate of Oman
| | - C R Hiley
- Department of Pharmacology, University of Cambridge, Cambridge, UK
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Lysophosphatidylinositol signalling: New wine from an old bottle. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:694-705. [DOI: 10.1016/j.bbalip.2012.01.009] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 12/02/2011] [Accepted: 01/03/2012] [Indexed: 01/29/2023]
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Ryu SK, Ahn DS, Cho YE, Choi SK, Kim YH, Morgan KG, Lee YH. Augmented sphingosylphosphorylcholine-induced Ca2+-sensitization of mesenteric artery contraction in spontaneously hypertensive rat. Naunyn Schmiedebergs Arch Pharmacol 2006; 373:30-6. [PMID: 16521007 DOI: 10.1007/s00210-006-0036-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2005] [Accepted: 01/10/2006] [Indexed: 10/24/2022]
Abstract
Sphingosylphosphorylcholine (SPC) is a vasoconstricting lysosphingolipid, and the RhoA/Rho-kinase pathway plays an important role in SPC-induced contraction. Since RhoA/Rho-kinase-mediated signaling is involved in the generation and/or maintenance of hypertension, we compared the effect of SPC on the contractility of endothelium-denuded small mesenteric arteries in spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Fura-2 Ca2+ signals, contractile responses, and phosphorylation of 20-kDa myosin light chains (MLC20) were measured. Ten microM SPC induced a gradual and sustained vasoconstriction, which was greater in arteries of the SHR (82.5 +/- 4.3%, n=9) than in those of the WKY (26.7 +/- 4.5%, n=10). In Ca2+-free media, SPC gradually increased vascular tone in the SHR, but caused little vasoconstriction in the WKY. In the SHR and WKY, SPC evoked a greater vasoconstriction than did high K+ depolarization at a given Ca2+ ratio, and the Ca2+ ratio-tension curve induced by SPC was significantly shifted to the left compared with that induced by high K+ depolarization. However, the magnitude of shift to the left was greater in the SHR than in the WKY. The Rho-kinase inhibitor Y-27632 significantly inhibited SPC-induced contractions, but neither the protein kinase C inhibitor calphostin-C nor PD98059, which inhibits activation of some mitogen-activated protein kinases, had any effect on the SHR or the WKY. SPC significantly increased the phosphorylation of MLC20 in both the SHR and the WKY, and Y-27632 inhibited the SPC-induced increase in MLC(20) phosphorylation in the SHR. Our results suggest that SPC induces greater vascular tone in the SHR than in the WKY. Furthermore, our results indicate that activation of the Rho-kinase pathway plays an important role in the SPC-induced Ca2+ sensitization in the SHR.
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Affiliation(s)
- Sung-Kyung Ryu
- Department of Physiology, College of Medicine, Yonsei University, C.P.O. Box 8044, Seoul, 120-752, South Korea
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Ding X, Murray PA. Cellular mechanisms of thromboxane A2-mediated contraction in pulmonary veins. Am J Physiol Lung Cell Mol Physiol 2005; 289:L825-33. [PMID: 15964897 DOI: 10.1152/ajplung.00177.2005] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Our objectives were to identify the relative contributions of [Ca2+]i and myofilament Ca2+ sensitivity in the pulmonary venous smooth muscle (PVSM) contractile response to the thromboxane A2 mimetic U-46619 and to assess the roles of PKC, tyrosine kinases (TK), and Rho-kinase (ROK) in that response. We tested the hypothesis that U-46619-induced contraction in PVSM is mediated by both increases in [Ca2+]i and myofilament Ca2+ sensitivity and that the PKC, TK, and ROK signaling pathways are involved. Isometric tension was measured in isolated endothelium-denuded (E-) canine pulmonary venous (PV) rings. In addition, [Ca2+]i and tension were simultaneously measured in fura-2-loaded E- PVSM strips. U-46619 (0.1 nM-1 microM) caused dose-dependent (P < 0.001) contraction in PV rings. U-46619 contraction was attenuated by inhibitors of L-type voltage-operated Ca2+ channels (nifedipine, P < 0.001), inositol 1,4,5-trisphosphate-mediated Ca2+ release (2-aminoethoxydiphenylborate, P < 0.001), PKC (bisindolylmaleimide I, P < 0.001), TK (tyrphostin A-47, P = 0.014), and ROK (Y-27632, P = 0.008). In PV strips, U-46619 contraction was associated with increases in [Ca2+]i and myofilament Ca2+ sensitivity. Both Ca2+ influx and release mediated the early transient increase in [Ca2+]i, whereas the late sustained increase in [Ca2+]i only involved Ca2+ influx. Inhibition of both PKC and ROK (P = 0.006 and P = 0.002, respectively), but not TK, attenuated the U-46619-induced increase in myofilament Ca2+ sensitivity. These results suggest that U-46619 contraction is mediated by Ca2+ influx, Ca2+ release, and increased myofilament Ca2+ sensitivity. The PKC, TK, and ROK signaling pathways are involved in U-46619 contraction.
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Affiliation(s)
- Xueqin Ding
- Center for Anesthesiology Research, The Cleveland Clinic Foundation, Cleveland, OH, USA
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Miao L, Dai Y, Zhang J. Mechanism of RhoA/Rho kinase activation in endothelin-1- induced contraction in rabbit basilar artery. Am J Physiol Heart Circ Physiol 2002; 283:H983-9. [PMID: 12181127 DOI: 10.1152/ajpheart.00141.2002] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This study was undertaken to demonstrate the role of the RhoA/Rho kinase pathway in endothelin-1 (ET-1)-induced contraction of the rabbit basilar artery. Isometric tension and Western blot were used to examine ET-1-induced contraction and RhoA activation. The upstream effect on ET-1-induced RhoA activity was determined by using ET(A) and ET(B) receptor antagonists, protein kinase C (PKC), tyrosine kinase, and phosphatidylinositol-3 kinase inhibitors. The downstream effect of ET-1-induced contraction and RhoA activity was studied in the presence of the Rho kinase inhibitor Y-27632. The effect of Rho kinase inhibitor on ET-1-induced myosin light chain (MLC) phosphorylation was investigated by using urea-glycerol-PAGE immunoblotting. We found 1) ET-1 increased RhoA activity (membrane binding RhoA) in a concentration-dependent manner; 2) ET(A), but not ET(B), receptor antagonist abolished the effect of ET-1 on RhoA activation; 3) phosphodylinositol-3 kinase inhibitor, but not PKC and tyrosine kinase inhibitors, reduced ET-1-induced RhoA activation; 4) Rho kinase inhibitor Y-27632 (10 microM) inhibited ET-1-induced contraction; and 5) ET-1 increased the level of MLC phosphorylation. Rho kinase inhibitor Y-27632 reduced the effect of ET-1 on MLC phosphorylation. This study demonstrated that RhoA/Rho kinase activation is involved in ET-1-induced contraction in the rabbit basilar artery. Phosphodylinositol-3 kinase and MLC might be the upstream and downstream factors of RhoA activation.
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Affiliation(s)
- Liyan Miao
- Department of Neurosurgery, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA
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Nobe K, Sakai Y, Maruyama Y, Momose K. Hyper-reactivity of diacylglycerol kinase is involved in the dysfunction of aortic smooth muscle contractility in streptozotocin-induced diabetic rats. Br J Pharmacol 2002; 136:441-51. [PMID: 12023947 PMCID: PMC1573360 DOI: 10.1038/sj.bjp.0704722] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. Dysfunction of vascular contraction in diabetes has been reported; however, the mechanisms are poorly understood. In this study, calcium sensitization involving increases in contraction in streptozotocin-induced diabetic rat aorta was detected. We hypothesize that an alteration in the intracellular signalling system plays a role in the dysfunction of vascular contractility in diabetes. Therefore, diacylglycerol (DG) kinase as a key enzyme of phosphatidylinositol (PI) turnover was investigated. 2. Treatment with norepinephrine (NE) caused time- and dose-dependent activation of DG kinase in control rats. This activation required simultaneous increases in intracellular calcium concentration ([Ca2+]i) and protein kinase C (PKC) activation. I3. n diabetic rats, hyper-reactivity of DG kinase involving inactivation in the resting state and over-activation in NE stimulation was observed. During hyper-reactivity, [Ca2+]i dependency of DG kinase was enhanced. Treatment with 50 mM KCl induced significant escalation in activity; moreover, basal activation of PKC was detected only in diabetes. These results suggested that PKC had been activated in the resting state. In contrast, these conditions were insufficient for DG kinase activation due to the absence of [Ca2+]i elevation. 4. During NE-stimulation, PKC activation was maintained and [Ca2+]i increased. Therefore, DG kinase was activated and an elevation in calcium dependency enhanced this activation. 5. The present study suggested that DG kinase hyper-reactivity in diabetes involved both an increase in [Ca2+]i and basal activation of PKC. This phenomenon may be associated with increased vascular contraction in diabetes mediated by acceleration of PI-turnover.
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Affiliation(s)
- Koji Nobe
- Department of Pharmacology, School of Pharmaceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku Tokyo, 142-8555 Japan.
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Martínez MC, Randriamboavonjy V, Ohlmann P, Komas N, Duarte J, Schneider F, Stoclet JC, Andriantsitohaina R. Involvement of protein kinase C, tyrosine kinases, and Rho kinase in Ca(2+) handling of human small arteries. Am J Physiol Heart Circ Physiol 2000; 279:H1228-38. [PMID: 10993789 DOI: 10.1152/ajpheart.2000.279.3.h1228] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The mechanisms of Ca(2+) handling and sensitization were investigated in human small omental arteries exposed to norepinephrine (NE) and to the thromboxane A(2) analog U-46619. Contractions elicited by NE and U-46619 were associated with an increase in intracellular Ca(2+) concentration ([Ca(2+)](i)), an increase in Ca(2+)-independent signaling pathways, or an enhancement of the sensitivity of the myofilaments to Ca(2+). The two latter pathways were abolished by protein kinase C (PKC), tyrosine kinase (TK), and Rho-associated protein kinase (ROK) inhibitors. In Ca(2+)-free medium, both NE and U-46619 elicited an increase in tension that was greatly reduced by PKC inhibitors and abolished by caffeine or ryanodine. After depletion of Ca(2+) stores with NE and U-46619 in Ca(2+)-free medium, addition of CaCl(2) in the continuous presence of the agonists produced increases in [Ca(2+)](i) and contractions that were inhibited by nitrendipine and TK inhibitors but not affected by PKC inhibitors. NE and U-46619 induced tyrosine phosphorylation of a 42- or a 58-kDa protein, respectively. These results indicate that the mechanisms leading to contraction elicited by NE and U-46619 in human small omental arteries are composed of Ca(2+) release from ryanodine-sensitive stores, Ca(2+) influx through nitrendipine-sensitive channels, and Ca(2+) sensitization and/or Ca(2+)-independent pathways. They also show that the TK pathway is involved in the tonic contraction associated with Ca(2+) entry, whereas TK, PKC, and ROK mechanisms regulate Ca(2+)-independent signaling pathways or Ca(2+) sensitization.
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Affiliation(s)
- M C Martínez
- Laboratoire de Pharmacologie et Physico-Chimie des Intéractions Cellulaires et Moléculaires, Unité Mixte de Recherche, Centre National pour les Recherches Scientifiques 7034, Université Louis Pasteur de Strasbourg, Faculté de Pharmacie, France
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Kureishi Y, Ito M, Feng J, Okinaka T, Isaka N, Nakano T. Regulation of Ca2+-independent smooth muscle contraction by alternative staurosporine-sensitive kinase. Eur J Pharmacol 1999; 376:315-20. [PMID: 10448893 DOI: 10.1016/s0014-2999(99)00367-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
It is well known that inhibition of myosin phosphatase induces smooth muscle contraction in the absence of Ca2+. We characterized the kinase(s) which plays a role in Ca2+-independent, microcystin-LR-induced contraction in permeabilized smooth muscle of the rabbit portal vein. Assessments of various protein kinase inhibitors revealed this kinase(s) (1) was sensitive to staurosporine (1 microM), but resistant to other agents including wortmannin (10 microM), Y-27632 ((R)-(+)-trans-N-(4-pyridyl)-4-(1-aminoethyl)-cyclohexanecarboxamide+ ++, 100 microM). HA1077 (1-(5-isoquinolinylsulfonyl)-homopiperazine, 100 microM), H-7 (1-(5-isoquinolinylsulfonyl)-2-methylpiperazine, 100 microM), and calphostin C (100 microM), and (2) induced phosphorylation of 20 kDa myosin light chain at serine-19. We concluded that other kinases exist which phosphorylate myosin light chain at serine-19 and induce Ca2+-independent smooth muscle contraction, distinct from Rho-associated kinase, myosin light chain kinase, and protein kinase C.
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Affiliation(s)
- Y Kureishi
- First Department of Internal Medicine, Mie University School of Medicine, Tsu, Japan
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Buus CL, Aalkjaer C, Nilsson H, Juul B, Møller JV, Mulvany MJ. Mechanisms of Ca2+ sensitization of force production by noradrenaline in rat mesenteric small arteries. J Physiol 1998; 510 ( Pt 2):577-90. [PMID: 9706005 PMCID: PMC2231048 DOI: 10.1111/j.1469-7793.1998.577bk.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
1. Mechanisms of Ca2+ sensitization of force production by noradrenaline were investigated by measuring contractile responses, intracellular Ca2+ concentration ([Ca2+]i) and phosphorylation of the myosin light chain (MLC) in intact and alpha-toxin-permeabilized rat mesenteric small arteries. 2. The effects of noradrenaline were investigated at constant membrane potential by comparing fully depolarized intact arteries in the absence and presence of noradrenaline. Contractile responses to K-PSS (125 mM K+) and NA-K-PSS (K-PSS + 10 microM noradrenaline) were titrated to 30 and 75%, respectively, of control force, by adjusting extracellular Ca2+ ([Ca2+]o). At both force levels, [Ca2+]i was substantially lower with NA-K-PSS than with K-PSS. With K-PSS, the proportion of MLC phosphorylated (approximately 30%) was similar at 30 and 75% of control force; with NA-K-PSS, MLC phosphorylation was greater at the higher force level (40 vs. 34%). 3. In alpha-toxin-permeabilized arteries, the force response to 1 microM Ca2+ was increased by 10 microM noradrenaline, and MLC phosphorylation was increased from 35 to 45%. The protein kinase C (PKC) inhibitor calphostin C (100 nM) abolished the noradrenaline-induced increase in MLC phosphorylation and contractile response, without affecting the contraction in response to Ca2+. Treatment with ATP gamma S in the presence of the MLC kinase inhibitor ML-9 increased the sensitivity to Ca2+ and abolished the response to noradrenaline. 4. The present results show that that in rat mesenteric small arteries noradrenaline-induced Ca2+ sensitization is associated with an increased proportion of phosphorylated MLC. The results are consistent with a decreased MLC phosphatase activity mediated through PKC. Furthermore, while MLC phosphorylation is a requirement for force production, the results show that other factors are also involved in force regulation.
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Affiliation(s)
- C L Buus
- Department of Pharmacology, University of Aarhus, Denmark.
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