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Mcleod RL, Erickson CH, Mingo GG, Hey JA. Intranasal Application of the α2-Adrenoceptor Agonist BHT-920 Produces Decongestion in the Cat. ACTA ACUST UNITED AC 2018. [DOI: 10.1177/194589240101500610] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The effect of α2-selective adrenoreceptor activation on nasal cavity dimension in an experimental model of congestion has not been defined. Presently, we used acoustic rhinometry to evaluate the decongestant activity of BHT-920, a selective α2-adrenergic agonist against nasal congestion produced by intranasal compound 48/80. Administration of the mast cell liberator compound 48/80 (1%) into a nasal passageway decreased ipsilateral volume and minimum cross-sectional area by 73 ± 4% and 42 ± 6%, respectively. The congestant effect of compound 48/80 was blocked by topical BHT-920 (0.3 and 1%) in a dose related manner. In addition, the decrease in minimum cross-sectional area produced by compound 48/80 was attenuated after topical BHT-920 treatment. As a comparison we also evaluated the topical decongestant activity effects of the α1-adrenergic agonist phenylephrine, and the nonselective α-agonist oxymetazoline. Both phenylephrine (0.1–1.0%) and oxymetazoline (0.01–0.3%) produced decongestion. The blood pressure effects of these three drugs also were evaluated. At doses of 0.3 and 1.0%, BHT-920 did not produce hypertension. In contrast, oxymetazoline (0.01–0.1%) produced a transient hypertension that peaked at 15 minutes and fully recovered 45 minutes after administration. The hypertensive effect of phenylephrine at 0.3 and 1.0% lasted over 60 minutes. The present findings indicate that selective α2-agonists may produce decongestant activity with an improved cardiovascular profile compared with current sympathomimetic drugs such as phenylephrine.
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Affiliation(s)
- Robbie L. Mcleod
- Allergy, Schering-Plough Research Institute, Kenilworth, New Jersey
| | | | | | - John A. Hey
- Allergy, Schering-Plough Research Institute, Kenilworth, New Jersey
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Synthesis, biological evaluation and structure–activity relationships of new phthalazinedione derivatives with vasorelaxant activity. Eur J Med Chem 2014; 82:407-17. [DOI: 10.1016/j.ejmech.2014.05.052] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Revised: 05/19/2014] [Accepted: 05/22/2014] [Indexed: 11/18/2022]
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Baptista RDFF, Taipeiro EDF, Queiroz RHC, Chies AB, Cordellini S. Stress alone or associated with ethanol induces prostanoid release in rat aorta via alpha2-Adrenoceptor. Arq Bras Cardiol 2014; 102:211-8. [PMID: 24676223 PMCID: PMC3987321 DOI: 10.5935/abc.20140015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Accepted: 10/02/2013] [Indexed: 12/29/2022] Open
Abstract
Background Stress and ethanol are both, independently, important cardiovascular risk
factors. Objective To evaluate the cardiovascular risk of ethanol consumption and stress exposure,
isolated and in association, in male adult rats. Methods Rats were separated into 4 groups: Control, ethanol (20% in drinking water for 6
weeks), stress (immobilization 1h day/5 days a week for 6 weeks) and
stress/ethanol. Concentration-responses curves to noradrenaline - in the absence
and presence of yohimbine, L-NAME or indomethacin - or to phenylephrine were
determined in thoracic aortas with and without endothelium. EC50 and maximum
response (n=8-12) were compared using two-way ANOVA/Bonferroni method. Results Either stress or stress in association with ethanol consumption increased the
noradrenaline maximum responses in intact aortas. This hyper-reactivity was
eliminated by endothelium removal or by the presence of either indomethacin or
yohimbine, but was not altered by the presence of L-NAME. Meanwhile, ethanol
consumption did not alter the reactivity to noradrenaline. The phenylephrine
responses in aortas both with and without endothelium also remained unaffected
regardless of protocol. Conclusion Chronic stress increased rat aortic responses to noradrenaline. This effect is
dependent upon the vascular endothelium and involves the release of
vasoconstrictor prostanoids via stimulation of endothelial alpha-2 adrenoceptors.
Moreover, chronic ethanol consumption appeared to neither influence noradrenaline
responses in rat thoracic aorta, nor did it modify the increase of such responses
observed as a consequence of stress exposure.
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Affiliation(s)
| | | | - Regina Helena Costa Queiroz
- Departamento de Análise Clínica - Toxicológica e Ciência de Alimentos, Faculdade de Ciências Farmacêuticas, USP, São Paulo, SP, Brasil
| | - Agnaldo Bruno Chies
- Departamento de Farmacologia, Instituto de Biociências, Universidade Estadual Paulista, São Paulo, SP, Brasil
| | - Sandra Cordellini
- Departamento de Farmacologia, Instituto de Biociências, Universidade Estadual Paulista, São Paulo, SP, Brasil
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El-Hajj H, Chandrasekhar B, Kadavil EA, Oriowo MA. Interaction of BKCa channel modulators with adrenergic agonists in the rat aorta is influenced by receptor reserve. Vascul Pharmacol 2005; 41:119-24. [PMID: 15607494 DOI: 10.1016/j.vph.2004.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Our main objective was to study the interaction of BKCa channel modulators with adrenergic agonists UK 14304 and noradrenaline (NA), acting on alpha1-adrenoceptors, in the rat aorta and how this is affected by receptor reserve. NA and UK 14304 evoked concentration-dependent contractions of the rat aorta. UK 14304 was a partial agonist relative to NA in this preparation. The BK(Ca) channel blocker tetraethylammonium (TEA, 1 mM) and opener NS 1619 (3 x 10(-5) M) modulated NA- and UK 14304-induced contractions, and were more effective on UK 14304-induced contractions. TEA (1 mM) increased the maximum response to NA and UK 14304 by about 13% and 300%, respectively, while NS 1619 (3 x 10(-5) M) reduced the maximum response to UK 14304 by about 81% compared to 31% for noradrenaline. The effect of TEA on the noradrenaline concentration-response curve was increased after treatment of the aorta with phenoxybenzamine (PBZ), an irreversible alpha1-adrenoceptor antagonist, to reduce receptor reserve. We concluded that the interaction of BKCa channel modulators with alpha1-adrenergic agonists in the rat aorta was influenced by receptor reserve.
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Affiliation(s)
- Hanadi El-Hajj
- Department of Pharmacology and Toxicology, Faculty of Medicine, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait
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González-Gómez JC, Santana L, Uriarte E, Brea J, Villazón M, Loza MI, De Luca M, Rivas ME, Montenegro GY, Fontenla JA. New arylpiperazine derivatives with high affinity for alpha1A, D2 and 5-HT2A receptors. Bioorg Med Chem Lett 2003; 13:175-8. [PMID: 12482418 DOI: 10.1016/s0960-894x(02)00933-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A series of novel long-chain arylpiperazines bearing a coumarin fragment was synthesized and the compounds were evaluated for their affinity at alpha(1), D(2 )and 5-HT(2A) receptors. Most of the new compounds showed high affinity for the three types of receptors alpha(1A), D(2) and 5-HT(2A) which depends, fundamentally, on the substitution of the N(4) of the piperazine ring. From the series emerged compound 6, which had an haloperidol-like profile at D(2) and 5HT(2A) receptors (pK(i) values of 7.93 and 6.76 respectively). The higher alpha(1A) receptor affinity (pA(2)=9.07) of this compound could contribute to a more atypical antipsychotic profile than the haloperidol.
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MESH Headings
- Algorithms
- Animals
- Aorta, Thoracic/drug effects
- Coumarins/chemistry
- Dopamine Antagonists/pharmacology
- Haloperidol/pharmacology
- In Vitro Techniques
- Indicators and Reagents
- Male
- Muscle, Smooth, Vascular/drug effects
- Piperazines/chemical synthesis
- Piperazines/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptor, Serotonin, 5-HT2A
- Receptors, Adrenergic, alpha-1/drug effects
- Receptors, Dopamine D2/drug effects
- Receptors, Serotonin/drug effects
- Structure-Activity Relationship
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Affiliation(s)
- J C González-Gómez
- Department of Organic Chemistry, Faculty of Pharmacy, University of Santiago, Campus Sur s/n, E-15782 Santiago de Compostela, Spain.
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Ellershaw DC, Gurney AM. Mechanisms of hydralazine induced vasodilation in rabbit aorta and pulmonary artery. Br J Pharmacol 2001; 134:621-31. [PMID: 11588117 PMCID: PMC1572994 DOI: 10.1038/sj.bjp.0704302] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
1. The directly acting vasodilator hydralazine has been proposed to act at an intracellular site in vascular smooth muscle to inhibit Ca(2+) release. 2. This study investigated the mechanism of action of hydralazine on rabbit aorta and pulmonary artery by comparing its effects on the tension generated by intact and beta-escin permeabilized vessels and on the cytoplasmic Ca(2+) concentration, membrane potential and K(+) currents of isolated vascular smooth muscle cells. 3. Hydralazine relaxed pulmonary artery and aorta with similar potency. It was equally effective at inhibiting phasic and tonic contractions evoked by phenylephrine in intact vessels and contractions evoked by inositol 1,4,5 trisphosphate (IP(3)) in permeabilized vessels. 4. Hydralazine inhibited the contraction of permeabilized vessels and the increase in smooth muscle cell Ca(2+) concentration evoked by caffeine with similar concentration dependence, but with lower potency than its effect on IP(3) contractions. 5. Hydralazine had no effect on the relationship between Ca(2+) concentration and force generation in permeabilized vessels, but it slowed the rate at which maximal force was developed before, but not after, destroying sarcoplasmic reticulum function with the calcium ionophore, ionomycin. 6. Hydralazine had no effect on membrane potential or the amplitudes of K(+) currents recorded from isolated smooth muscle cells over the concentration range causing relaxation of intact vessels. 7. The results suggest that the main action of hydralazine is to inhibit the IP(3)-induced release of Ca(2+) from the sarcoplasmic reticulum in vascular smooth muscle cells.
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Affiliation(s)
- D C Ellershaw
- Department of Pharmacology, UMDS, St Thomas's Hospital, Lambeth Palace Road, London, SE1 7EH
| | - A M Gurney
- Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow, G4 ONR
- Author for correspondence:
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Suenaga H, Kamata K. Alpha-adrenoceptor agonists produce Ca2+ oscillations in isolated rat aorta: role of protein kinase C. J Smooth Muscle Res 2000; 36:205-18. [PMID: 11398898 DOI: 10.1540/jsmr.36.205] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We investigated the relationship between tension development and the cytosolic free Ca2+ level ([Ca2+]i) in responses to norepinephrine (NE) and selective alpha2-adrenoceptor agonist, UK14,304 of the endothelium-denuded rat aorta loaded with fura PE-3. NE (3 x 10(-8) M) evoked a rapid increase in [Ca2+]i followed by slight decreasing to a steady state level and produced a contraction. After the NE-induced increase in [Ca2+]i had reached a maximum, the [Ca2+]i showed persistent oscillations. The Ca2+ oscillations were superimposed on the sustained increase in [Ca2+]i. UK14,304 (3 x 10(-6) M) also evoked an increase in [Ca2+]i and produced a contraction. However, the UK14,304-induced effect on [Ca2+]i was characterized by pronounced oscillations, and the amplitude of the sustained increase in [Ca2+]i was less than that seen with NE. Protein kinase C inhibitor, Ro31-8220 (3 x 10(-6) M) and verapamil (10(-5) M) abolished both NE and UK14,304-evoked Ca2+ oscillations. UK14,304-induced contractions were also strongly inhibited by Ro31-8220 and verapamil. However, NE induced contractions were partly inhibited by these inhibitors. The sustained increases in [Ca2+]i evoked NE and UK14,304 were not significantly inhibited by Ro31-8220 and verapamil. These results suggest that NE and UK14,304 produce Ca2+ oscillations during sustained contractions in rat aorta. The alpha2 adrenoceptor agonist, UK14,304-induced sustained contraction and Ca2+ oscillations may be due to PKC activation and opening of voltage-dependent L type Ca2+ channels.
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Affiliation(s)
- H Suenaga
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Tokyo, Japan
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Campos-Toimil M, Estévez I, Raviña E, Orallo F. Pyridazine derivatives XIV. Study of the vasorelaxant action of 6-aryl-5-piperidino-3-hydrazinopyridazines in isolated rat thoracic aorta: comparison with hydralazine. GENERAL PHARMACOLOGY 1998; 30:201-7. [PMID: 9580127 DOI: 10.1016/s0306-3623(97)00108-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
1. For several years we have been working on the synthesis of modified hydrazinopyridazines which have proved to possess remarkable vasorelaxant and antihypertensive activity. We now report the vasodilator effects of three novel 6-aryl-5-piperidino-3-hydrazinopyridazines (1a, 1b and 1c), structurally related to the well-known antihypertensive drug hydralazine. 2. Hydralazine and the new hydrazinopyridazines relaxed, in a concentration-dependent and nonspecific way, the contractions elicited by noradrenaline or a high K+ concentration in rat aortic rings with or without endothelium. According to the IC50 (50% inhibitory concentrations) values obtained, the vasorelaxant potency of the new compounds was greater than that of hydralazine. 3. In a Ca2+-free medium, the contractions provoked by noradrenaline or caffeine were significantly inhibited by the new hydrazinopyridazines and by hydralazine. 4. Hydralazine and the novel molecules did not significantly modify basal, noradrenaline- or K+-induced 45Ca2+ uptake. 5. These results suggest that 1a, 1b and 1c have an endothelium-independent vasorelaxant activity greater than that of hydralazine in isolated rat aortic rings, which seems not to be mediated by a blockade of transmembrane Ca2+ movements through specific channels. This effect could be due, at least in part, to an intracellular mechanism of action.
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Affiliation(s)
- M Campos-Toimil
- Departamento de Farmacología, Facultad de Farmacia, Universidad de Santiago de Compostela, Campus Universitario Sur, Spain
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Orallo F. Study of the in vivo and in vitro cardiovascular effects of a hydralazine-like vasodilator agent (HPS-10) in normotensive rats. Br J Pharmacol 1997; 121:1627-36. [PMID: 9283696 PMCID: PMC1564871 DOI: 10.1038/sj.bjp.0701314] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
1. In this work, the cardiovascular effects of HPS-10, a new vasodilator agent, were studied in rats. 2. In conscious normotensive rats, oral administration of HPS-10 (4-9 mg kg-1) produced a dose-related and long-lasting fall in systolic arterial blood pressure (ED30 of 5.32 mg kg-1), accompanied by an increase in heart rate (ED30 of 8.43 mg kg-1). This tachycardia was totally inhibited by pretreatment with (+/-)-propranolol (10 mg kg-1, p.o.). 3. In anaesthetized normotensive rats, HPS-10 (0.3-0.6 mg kg-1, i.v.) produced a gradual, dose-dependent and sustained decrease in systolic, diastolic and mean arterial pressure (MAP) (ED30 for MAP of 0.41 mg kg-1, i.v.), accompanied by a significant bradycardia at high doses (> 0.4 mg kg-1; ED20 of 0.61 mg kg-1, i.v.). HPS-10 (0.5 mg kg-1, i.v.) did not modify the positive chronotropic effects induced by intravenous administration of noradrenaline (NA; 5 micrograms kg-1), angiotensin II (AII; 0.2 microgram kg-1) and nicotine (200 micrograms kg-1) but markedly inhibited the hypertensive response produced by these agents. 4. In rat isolated rubbed aorta, HPS-10 (0.1-1 mM) non-competitively and with almost equal effectiveness antagonized the contractions induced by NA, AII (in normal Krebs solution) and Ca2+ (in depolarizing Ca(2+)-free high-K+ 50 mM solution). In the experiments in Ca(2+)-free medium, HPS-10 (1 mM) considerably inhibited the contractions induced by NA, AII and caffeine in rat aorta. 5. Furthermore, in the studies with radioactive Ca2+, HPS-10 (1 mM) did not modify the basal uptake of 45Ca2+ but strongly decreased the influx of 45Ca2+ induced by NA, AII and K+ in rat aortic rings. 6. In rat isolated atria, HPS-10 (1 mM) produced a positive inotropic/negative chronotropic effect. 7. HPS-10 (0.3 mM) significantly inhibited the sustained and transient Ba2+ inward current (IBa) recorded in whole-cell clamped rat aortic myocytes. 8. These results indicate that the non-selective vasorelaxant effects of HPS-10 in rat aortic rings can be attributed to transmembrane Ca(2+)-antagonist activity and an intracellular action on smooth muscle cells. The direct vasodilator action of HPS-10 observed in rat isolated aorta may be responsible for the HPS-10 hypotensive activity in anaesthetized normotensive rats.
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Affiliation(s)
- F Orallo
- Departamento de Farmacología, Facultad de Farmacia, Universidad de Santiago de Compostela, España
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