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Chen N, Lv J, Bo L, Li N, Wu C, Yin X, Li J, Tao J, Chen J, He Y, Huang S, Xiao J, Mao C, Xu Z. Muscarinic-mediated vasoconstriction in human, rat and sheep umbilical cords and related vasoconstriction mechanisms. BJOG 2014; 122:1630-9. [PMID: 25403992 DOI: 10.1111/1471-0528.13144] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2014] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The umbilical cord provides nutrition and oxygen to the fetus. The aim of this study was to determine the effects of acetylcholine (ACh) on umbilical cords from humans and other mammals, and the mechanisms of ACh-mediated vasoconstriction in the human umbilical cord. DESIGN Human and animal umbilical cords used in vascular and cellular experiments. SETTING Institute for Fetology, First Hospital of Soochow University, Suzhou, China. POPULATION A total of 85 pregnant women, 16 Sprague Dawley rats and seven pregnant sheep. METHODS Umbilical cord veins and arteries from humans, rats and sheep, aortas and mesenteric arteries from rats, and mesenteric, carotid and femoral arteries from ovine fetuses were used to compare vascular functions in response to ACh and to determine the mechanisms of ACh-mediated umbilical vasoconstriction. Vascular tension and ion channel currents were measured on isolated vessels and smooth muscle cells from human umbilical cords. MAIN OUTCOME MEASURES Provision of new evidence to conclude that ACh-stimulated vasoconstriction is common to all umbilical cords, and cellular mechanisms are linked to potassium channels. RESULTS ACh caused reliable vasoconstriction in umbilical veins/arteries in humans, rats and sheep, but not in any other vessels, including fetal vessels. Atropine inhibited the effects of ACh. The mRNA of ACh-muscarinic receptor subtypes M1 -M5 was expressed in human umbilical vessels. The protein kinase C antagonist GF109203X and the calcium inhibitor nifedipine decreased ACh-induced vasoconstriction in human umbilical vessels. ACh also caused a reduction in whole-cell potassium channel currents and the single-channel current of large-conductance calcium-activated potassium (BKca) channels. CONCLUSION Umbilical vessels are significantly different from other vessels in their response to ACh. BKca channels in smooth muscle cells may play important roles in ACh-mediated vasoconstriction in human umbilical cords. This information may be important for fetal medicine and practice with regard to the effect on fetal development of umbilical vascular functions.
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Affiliation(s)
- N Chen
- Institute for Fetology and Reproductive Medicine Center, First Hospital of Soochow University, Suzhou, China
| | - J Lv
- Institute for Fetology and Reproductive Medicine Center, First Hospital of Soochow University, Suzhou, China
| | - L Bo
- Institute for Fetology and Reproductive Medicine Center, First Hospital of Soochow University, Suzhou, China
| | - N Li
- Institute for Fetology and Reproductive Medicine Center, First Hospital of Soochow University, Suzhou, China
| | - C Wu
- Institute for Fetology and Reproductive Medicine Center, First Hospital of Soochow University, Suzhou, China
| | - X Yin
- Institute for Fetology and Reproductive Medicine Center, First Hospital of Soochow University, Suzhou, China
| | - J Li
- Institute for Fetology and Reproductive Medicine Center, First Hospital of Soochow University, Suzhou, China
| | - J Tao
- Institute for Fetology and Reproductive Medicine Center, First Hospital of Soochow University, Suzhou, China
| | - J Chen
- Institute for Fetology and Reproductive Medicine Center, First Hospital of Soochow University, Suzhou, China
| | - Y He
- Institute for Fetology and Reproductive Medicine Center, First Hospital of Soochow University, Suzhou, China
| | - S Huang
- Institute for Fetology and Reproductive Medicine Center, First Hospital of Soochow University, Suzhou, China
| | - J Xiao
- Institute for Fetology and Reproductive Medicine Center, First Hospital of Soochow University, Suzhou, China
| | - C Mao
- Institute for Fetology and Reproductive Medicine Center, First Hospital of Soochow University, Suzhou, China
| | - Z Xu
- Institute for Fetology and Reproductive Medicine Center, First Hospital of Soochow University, Suzhou, China.,Center for Prenatal Biology, Loma Linda University, Lorna Linda, CA, USA
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Mitchelson FJ. The pharmacology of McN-A-343. Pharmacol Ther 2012; 135:216-45. [DOI: 10.1016/j.pharmthera.2012.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 05/07/2012] [Indexed: 01/01/2023]
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Cansev M, Yilmaz MS, Ilcol YO, Hamurtekin E, Ulus IH. Cardiovascular effects of CDP-choline and its metabolites: involvement of peripheral autonomic nervous system. Eur J Pharmacol 2007; 577:129-42. [PMID: 17884041 DOI: 10.1016/j.ejphar.2007.08.029] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Revised: 07/01/2007] [Accepted: 08/22/2007] [Indexed: 11/25/2022]
Abstract
Intraperitoneal administration of CDP-choline (200-900 micromol/kg) increased blood pressure and decreased heart rate of rats in a dose- and time-dependent manner. These responses were accompanied by elevated serum concentrations of CDP-choline and its metabolites phosphocholine, choline, cytidine monophosphate and cytidine. Blood pressure increased by intraperitoneal phosphocholine (200-900 micromol/kg), while it decreased by choline (200-600 micromol/kg) administration; phosphocholine or choline administration (up to 600 micromol/kg) decreased heart rate. Intraperitoneal cytidine monophosphate (200-600 micromol/kg) or cytidine (200-600 micromol/kg) increased blood pressure without affecting heart rate. Pressor responses to CDP-choline, phosphocholine, cytidine monophosphate or cytidine were not altered by pretreatment with atropine methyl nitrate or hexamethonium while hypotensive effect of choline was reversed to pressor effect by these pretreatments. Pretreatment with atropine plus hexamethonium attenuated or blocked pressor response to CDP-choline or phosphocholine, respectively. Heart rate responses to CDP-choline, phosphocholine and choline were blocked by atropine and reversed by hexamethonium. Cardiovascular responses to CDP-choline, phosphocholine and choline, but not cytidine monophosphate or cytidine, were associated with elevated plasma catecholamines concentrations. Blockade of alpha-adrenoceptors by prazosin or yohimbine attenuated pressor response to CDP-choline while these antagonists blocked pressor responses to phosphocholine or choline. Neither bilateral adrenalectomy nor chemical sympathectomy altered cardiovascular responses to CDP-choline, choline, cytidine monophosphate or cytidine. Sympathectomy attenuated pressor response to phosphocholine. Results show that intraperitoneal administration of CDP-choline and its metabolites alter cardiovascular parameters and suggest that peripheral cholinergic and adrenergic receptors are involved in these responses.
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Affiliation(s)
- Mehmet Cansev
- Department of Pharmacology and Clinical Pharmacology, Uludag University School of Medicine, Gorukle, Bursa 16059, Turkey.
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Jones CK, Eberle EL, Shaw DB, McKinzie DL, Shannon HE. Pharmacologic Interactions between the Muscarinic Cholinergic and Dopaminergic Systems in the Modulation of Prepulse Inhibition in Rats. J Pharmacol Exp Ther 2004; 312:1055-63. [PMID: 15574685 DOI: 10.1124/jpet.104.075887] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Prepulse inhibition (PPI) of the acoustic startle reflex is a sensorimotor gating process known to be deficient in a number of neurologic and psychiatric conditions, including schizophrenia. Multiple lines of evidence have indicated that the dopaminergic and muscarinic cholinergic systems play an important role in modulating PPI. Moreover, interactions between the dopaminergic and muscarinic cholinergic systems are well known; however, little is known about potential interactions between the two systems in modulating PPI. Therefore, the purpose of the present studies was to determine whether interactions occur between the muscarinic cholinergic and dopaminergic systems in modulating PPI. The efficacy of muscarinic cholinergic receptor agonists in reversing the disruption of PPI induced by apomorphine, a D1/D2 dopamine receptor agonist, was evaluated in male Sprague-Dawley rats. The M1/M4-preferring muscarinic agonist xanomeline and the M2/M4-preferring agonist BuTAC [([5R-[exo]-6-[butylthio]-1,2,5-thiadiazol-3-yl-]-1-azabyciclo-[3.2.1])octane oxalate] reversed the apomorphine-induced disruption of PPI in a manner similar to that produced by the D2-like dopamine receptor antagonists haloperidol and olanzapine. The muscarinic agonists oxotremorine, RS86 [[2-ethyl-8-methyl-2,8-diazaspiro(4.5)decane-1,3-dione] hydrochloride], pilocarpine, milameline, and sabcomeline also reversed the apomorphine-induced disruption of PPI. Moreover, the muscarinic antagonist scopolamine also disrupted PPI, and the D2-like receptor antagonist haloperidol, but not the D1-like receptor antagonist SCH23390 [R-(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine], reversed the scopolamine-induced disruption. In addition, xanomeline produced a significant reversal of the disruption in PPI produced by scopolamine. Collectively, the present findings demonstrate that a functional interaction occurs between the muscarinic cholinergic and dopaminergic systems in modulating PPI and that muscarinic cholinergic agonists may be effective in the treatment of the PPI and other cognitive impairments observed in schizophrenia.
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Affiliation(s)
- Carrie K Jones
- Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285, USA
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Lamping KG, Wess J, Cui Y, Nuno DW, Faraci FM. Muscarinic (M) Receptors in Coronary Circulation. Arterioscler Thromb Vasc Biol 2004; 24:1253-8. [PMID: 15130910 DOI: 10.1161/01.atv.0000130661.82773.ca] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Determining the role of specific muscarinic (M) receptor subtypes mediating responses to acetylcholine (ACh) has been limited by the specificity of pharmacological agents. Deletion of the gene for M5 receptors abolished response to ACh in cerebral blood vessels but did not affect dilation of coronary arteries. The goal of this study was to determine the M receptors mediating responses to ACh in coronary circulation using mice deficient in M2 or M3 receptors (M2-/-, M3-/-, respectively). METHODS AND RESULTS Coronary arteries from respective wild-type, M2-/-, or M3-/- mice were isolated, cannulated, and pressurized. Diameter was measured with video microscopy. After preconstriction with U46619, ACh produced dose-dependent dilation of coronary arteries that was similar in wild-type and M2-/- mice. In contrast, dilation of coronary arteries from M3-/- mice to ACh was reduced by approximately 80% compared with wild type. The residual response to ACh was atropine insensitive. Relaxation of coronary arteries to other stimuli was similar in M2-/- and M3-/- mice. Similar results were obtained in aorta rings. CONCLUSIONS These findings provide the first direct evidence that relaxation to ACh in coronary circulation is mediated predominantly by activation of M3 receptors.
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MESH Headings
- 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid/pharmacology
- Acetylcholine/pharmacology
- Animals
- Aorta, Thoracic
- Atropine/pharmacology
- Cholinergic Agents/pharmacology
- Coronary Circulation/physiology
- Coronary Vessels
- Male
- Mice
- Mice, Knockout
- Muscarinic Antagonists/pharmacology
- Nitroprusside/pharmacology
- Papaverine/pharmacology
- RNA, Messenger/biosynthesis
- Receptor, Muscarinic M1/biosynthesis
- Receptor, Muscarinic M1/genetics
- Receptor, Muscarinic M3/deficiency
- Receptor, Muscarinic M3/drug effects
- Receptor, Muscarinic M3/genetics
- Receptor, Muscarinic M3/physiology
- Receptor, Muscarinic M4/biosynthesis
- Receptor, Muscarinic M4/genetics
- Receptor, Muscarinic M5/biosynthesis
- Receptor, Muscarinic M5/genetics
- Vasodilation/drug effects
- Vasodilation/physiology
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Affiliation(s)
- Kathryn G Lamping
- Department of Internal Medicine and Pharmacology, University of Iowa, Roy J. and Lucille A. Carver School of Medicine and the Veterans Administration, Iowa City, IA 52246, USA.
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Fisher JT, Vincent SG, Gomeza J, Yamada M, Wess J. Loss of vagally mediated bradycardia and bronchoconstriction in mice lacking M2 or M3 muscarinic acetylcholine receptors. FASEB J 2004; 18:711-3. [PMID: 14977875 DOI: 10.1096/fj.03-0648fje] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The presence of multiple muscarinic acetylcholine receptor (mAChR) subtypes in the heart and lung, combined with the lack of mAChR subtype-selective ligands, have complicated the task of identifying the mAChR subtypes mediating cardiac slowing (bradycardia) and airway narrowing (bronchoconstriction) due to vagal innervation. To determine which of the five mAChRs are responsible for the cholinergic control of heart rate and airway caliber in vivo, we performed experiments on mutant mice lacking the two prime candidates for such control, the M2 or M3 mAChR. Here, we report that in vivo, bradycardia caused by vagal stimulation or administration of the muscarinic agonist methacholine (MCh) was abolished in mice lacking functional M2 mAChRs (M2-/- mice). In contrast, heart rate responses remained unchanged in M3 receptor-deficient mice (M3-/- mice). The reduced hypotensive response of M3-/- mice to MCh suggests M3 mAChRs contribute to peripheral vasodilation. The M2-/- mice showed significantly enhanced in vivo bronchoconstrictor responses to vagal stimulation or MCh administration. In contrast, bronchoconstrictor responses were totally abolished in M3-/- mice. Because altered cardiac or pulmonary vagal tone is involved in a number of pathophysiological conditions, including cardiac arrhythmias, chronic obstructive pulmonary disease and asthma, these results should be of considerable therapeutic relevance.
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Affiliation(s)
- John T Fisher
- Department of Physiology, Queen's University, Kingston, Ontario, Canada K7L 3N6.
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Scheidweiler KB, Plessinger MA, Shojaie J, Wood RW, Kwong TC. Pharmacokinetics and Pharmacodynamics of Methylecgonidine, a Crack Cocaine Pyrolyzate. J Pharmacol Exp Ther 2003; 307:1179-87. [PMID: 14561847 DOI: 10.1124/jpet.103.055434] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Methylecgonidine is formed from cocaine base when smoked and has been identified in biological fluids of crack smokers. Ecgonidine, a metabolite of methylecgonidine formed via esterase activity, also has been identified in similar samples collected from crack smokers. Methylecgonidine and ecgonidine can be used as biomarkers to differentiate smoking from cocaine use via other routes of administration. We determined the pharmacokinetic properties of methylecgonidine and ecgonidine in sheep after intravenous administration of methylecgonidine at doses of 3.0, 5.6, and 10.0 mg/kg using gas chromatography-mass spectrometric assays. Methylecgonidine clears quickly from blood with a half-life of 18 to 21 min, whereas ecgonidine has a longer half-life of 94 to 137 min. Because ecgonidine clears more slowly, it may be a more effective biomarker of cocaine smoking. The cardiovascular stimulant effects of cocaine contrast with reported in vitro muscarinic agonist effects of methylecgonidine, decreasing contractility and stimulating nitric oxide production in cardiac cells and tissues. To test the hypothesis that methylecgonidine produces cardiovascular effects in vivo consistent with muscarinic agonism, methylecgonidine was administered to sheep intravenously (0.1-3.0 mg/kg) while monitoring heart rate and blood pressure. Significant hypotension and tachycardia occurred in all three sheep. Two of the three sheep demonstrated mild bradycardia 3 to 5 min after methylecgonidine injection. Intravenous pretreatment with atropine methyl bromide (15 microg/kg) antagonized methylecgonidine-induced hypotension in all three sheep, supporting the hypothesis that methylecgonidine acts as a muscarinic agonist in vivo.
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Martínez AC, Hernández M, Rivera L, Recio P, García-Sacristán A, Benedito S. Muscarinic receptor subtypes mediate vasorelaxation in isolated horse deep dorsal penile vein. Urology 2003; 62:357-61. [PMID: 12893364 DOI: 10.1016/s0090-4295(03)00253-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES To investigate the effect of acetylcholine (ACh) on horse deep dorsal penile vein and to characterize the muscarinic receptor subtypes involved in this response. METHODS Vein rings were mounted in an organ bath chamber, and the isometric tension was recorded. RESULTS In phenylephrine-contracted veins, ACh (1 nM to 1 microM) induced endothelium-dependent relaxation. The muscarinic receptor antagonist, atropine, produced parallel rightward shifts of the ACh response curves (pA2 = 10.04; pK(B) = 9.98). Carbachol (10 nM to 100 microM) also evoked relaxation in the vein segments, but showed a lower potency and similar relaxation to that induced by ACh. Pirenzepine, the high, intermediate, and low-affinity antagonist for M1, M3, and M2 receptors, respectively, inhibited ACh and carbachol-induced relaxation, yielding pA2 values of 7.51 and 7.37, and pK(B) values of 7.38 and 7.28, respectively. Methoctramine, a high-affinity M2 antagonist, showed no significant effect on the response to ACh. However, a high-affinity M3 antagonist, pFHHSiD, potently blocked the relaxation induced by carbachol and ACh, yielding pA2 and pK(B) values of 7.72 and 7.70 for pFHHSiD against ACh, respectively, and of 7.77 and 7.65 against carbachol, respectively. CONCLUSIONS These results indicate that ACh induces an endothelium-dependent relaxation in horse deep dorsal penile vein. The antagonist profile suggests that M3 muscarinic receptors mediate ACh-induced relaxation in this tissue.
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Affiliation(s)
- Ana Cristina Martínez
- Sección Departamental de Fisiología, Facultad de Farmacia, Universidad Complutense, Madrid, Spain
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Abstract
Snake envenomation employs three well integrated strategies: prey immobilization via hypotension, prey immobilization via paralysis, and prey digestion. Purines (adenosine, guanosine and inosine) evidently play a central role in the envenomation strategies of most advanced snakes. Purines constitute the perfect multifunctional toxins, participating simultaneously in all three envenomation strategies. Because they are endogenous regulatory compounds in all vertebrates, it is impossible for any prey organism to develop resistance to them. Purine generation from endogenous precursors in the prey explains the presence of many hitherto unexplained enzyme activities in snake venoms: 5'-nucleotidase, endonucleases (including ribonuclease), phosphodiesterase, ATPase, ADPase, phosphomonoesterase, and NADase. Phospholipases A(2), cytotoxins, myotoxins, and heparinase also participate in purine liberation, in addition to their better known functions. Adenosine contributes to prey immobilization by activation of neuronal adenosine A(1) receptors, suppressing acetylcholine release from motor neurons and excitatory neurotransmitters from central sites. It also exacerbates venom-induced hypotension by activating A(2) receptors in the vasculature. Adenosine and inosine both activate mast cell A(3) receptors, liberating vasoactive substances and increasing vascular permeability. Guanosine probably contributes to hypotension, by augmenting vascular endothelial cGMP levels via an unknown mechanism. Novel functions are suggested for toxins that act upon blood coagulation factors, including nitric oxide production, using the prey's carboxypeptidases. Leucine aminopeptidase may link venom hemorrhagic metalloproteases and endogenous chymotrypsin-like proteases with venom L-amino acid oxidase (LAO), accelerating the latter. The primary function of LAO is probably to promote prey hypotension by activating soluble guanylate cyclase in the presence of superoxide dismutase. LAO's apoptotic activity, too slow to be relevant to prey capture, is undoubtedly secondary and probably serves principally a digestive function. It is concluded that the principal function of L-type Ca(2+) channel antagonists and muscarinic toxins, in Dendroaspis venoms, and acetylcholinesterase in other elapid venoms, is to promote hypotension. Venom dipeptidyl peptidase IV-like enzymes probably also contribute to hypotension by destroying vasoconstrictive peptides such as Peptide YY, neuropeptide Y and substance P. Purines apparently bind to other toxins which then serve as molecular chaperones to deposit the bound purines at specific subsets of purine receptors. The assignment of pharmacological activities such as transient neurotransmitter suppression, histamine release and antinociception, to a variety of proteinaceous toxins, is probably erroneous. Such effects are probably due instead to purines bound to these toxins, and/or to free venom purines.
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Affiliation(s)
- Steven D Aird
- Laboratório de Toxinas Naturais, Universidade Estadual do Ceará, Avenida Paranjana, 1700, Itaperí, 60740-000, Fortaleza, CE, Brazil.
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Abstract
The control and maintenance of vascular tone is due to a balance between vasoconstrictor and vasodilator pathways. Vasomotor responses to neural, metabolic and physical factors vary between vessels in different vascular beds, as well as along the same bed, particularly as vessels become smaller. These differences result from variation in the composition of neurotransmitters released by perivascular nerves, variation in the array and activation of receptor subtypes expressed in different vascular beds and variation in the signal transduction pathways activated in either the vascular smooth muscle or endothelial cells. As the study of vasomotor responses often requires pre-existing tone, some of the reported heterogeneity in the relative contributions of different vasodilator mechanisms may be compounded by different experimental conditions. Biochemical variations, such as the expression of ion channels, connexin subtypes and other important components of second messenger cascades, have been documented in the smooth muscle and endothelial cells in different parts of the body. Anatomical variations, in the presence and prevalence of gap junctions between smooth muscle cells, between endothelial cells and at myoendothelial gap junctions, between the two cell layers, have also been described. These factors will contribute further to the heterogeneity in local and conducted responses.
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Affiliation(s)
- C E Hill
- Autonomic Synapse Group, Division of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra 0200 ACT, Australia.
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