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Epstein M, Bali K, Piggot TJ, Green AC, Timperley CM, Bird M, Tattersall JEH, Bermudez I, Biggin PC. Molecular determinants of binding of non-oxime bispyridinium nerve agent antidote compounds to the adult muscle nAChR. Toxicol Lett 2021; 340:114-122. [PMID: 33482275 DOI: 10.1016/j.toxlet.2021.01.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 01/11/2021] [Accepted: 01/11/2021] [Indexed: 11/27/2022]
Abstract
Organophosphorus nerve agents (NAs) are the most lethal chemical warfare agents and have been used by state and non-state actors since their discovery in the 1930s. They covalently modify acetylcholinesterase, preventing the breakdown of acetylcholine (ACh) with subsequent loss of synaptic transmission, which can result in death. Despite the availability of several antidotes for OPNA exposure, none directly targets the nicotinic acetylcholine receptor (nAChR) mediated component of toxicity. Non-oxime bispyridinium compounds (BPDs) have been shown previously to partially counteract the effects of NAs at skeletal muscle tissue, and this has been attributed to inhibition of the muscle nAChR. Functional data indicate that, by increasing the length of the alkyl linker between the pyridinium moieties of BPDs, the antagonistic activity at nAChRs can be improved. Molecular dynamics simulations of the adult muscle nAChR in the presence of BPDs identified key residues likely to be involved in binding. Subsequent two-electrode voltage clamp recordings showed that one of the residues, εY131, acts as an allosteric determinant of BPD binding, and that longer BPDs have a greater stabilizing effect on the orthosteric loop C than shorter ones. The work reported will inform future design work on novel antidotes for treating NA exposure.
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Affiliation(s)
- Max Epstein
- Department of Biochemistry, Structural Bioinformatics and Computational Biochemistry, University of Oxford, Oxford, UK
| | - Karan Bali
- Department of Biochemistry, Structural Bioinformatics and Computational Biochemistry, University of Oxford, Oxford, UK; Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, UK
| | - Thomas J Piggot
- Chemical, Biological and Radiological Sciences Division, Defence Science and Technology Laboratory (DSTL), Porton Down, Salisbury, Wiltshire, UK
| | - A Christopher Green
- Chemical, Biological and Radiological Sciences Division, Defence Science and Technology Laboratory (DSTL), Porton Down, Salisbury, Wiltshire, UK
| | - Christopher M Timperley
- Chemical, Biological and Radiological Sciences Division, Defence Science and Technology Laboratory (DSTL), Porton Down, Salisbury, Wiltshire, UK
| | - Mike Bird
- Chemical, Biological and Radiological Sciences Division, Defence Science and Technology Laboratory (DSTL), Porton Down, Salisbury, Wiltshire, UK
| | - John E H Tattersall
- Chemical, Biological and Radiological Sciences Division, Defence Science and Technology Laboratory (DSTL), Porton Down, Salisbury, Wiltshire, UK
| | - Isabel Bermudez
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK
| | - Philip C Biggin
- Department of Biochemistry, Structural Bioinformatics and Computational Biochemistry, University of Oxford, Oxford, UK.
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Shaydenfish D, Wongtangman K, Eikermann M, Schaefer MS. The effects of acetylcholinesterase inhibitors on morbidity after general anesthesia and surgery. Neuropharmacology 2020; 173:108134. [PMID: 32416089 DOI: 10.1016/j.neuropharm.2020.108134] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 04/24/2020] [Accepted: 05/08/2020] [Indexed: 12/20/2022]
Abstract
Non-depolarizing neuromuscular blocking agents are used during general anesthesia to facilitate intubation and optimize surgical conditions. When patients leave the operating room after surgery, postoperative residual neuromuscular block occurs frequently, increasing vulnerability to respiratory complications such as hypoxemia and unplanned postoperative mechanical ventilation. To restore neuromuscular transmission and skeletal muscle strength, anesthesiologists typically administer peripherally acting acetylcholinesterase inhibitors such as neostigmine. However, neostigmine's desirable effects have a narrow therapeutic range. Even at recommended dose (15-50 μg/kg), neostigmine induces nicotinic (upper airway muscle weakness leading to dysphagia and upper airway obstruction, and decreased maximum inspiratory airflow) and muscarinic (blurred vision, bronchial constriction, abdominal cramping and nausea) side effects. Recent data have questioned as to whether neostigmine reversal of neuromuscular blockade improves relevant patient outcomes such as postoperative respiratory and perioperative cardiovascular complications. A central strategy to avoid side effects of neuromuscular blocking agents is their judicious use based on quantitative monitoring of neuromuscular transmission using repetitive peripheral nerve stimulation (train-of-four ratio). Peripherally acting acetylcholinesterase inhibitors such as neostigmine should then only be administered when indicated and dosed based on results of the train-of-four ratio.
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Affiliation(s)
- Denys Shaydenfish
- Department of Anesthesia, Critical Care & Pain Medicine, Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, MA, USA
| | - Karuna Wongtangman
- Department of Anesthesia, Critical Care & Pain Medicine, Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, MA, USA; Department of Anesthesiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Matthias Eikermann
- Department of Anesthesia, Critical Care & Pain Medicine, Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, MA, USA; Department of Anaesthesiology & Intensive Care Medicine, University of Duisburg-Essen, Essen, Germany.
| | - Maximilian S Schaefer
- Department of Anesthesia, Critical Care & Pain Medicine, Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, MA, USA; Department of Anaesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany
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3
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Ring A, Strom BO, Turner SR, Timperley CM, Bird M, Green AC, Chad JE, Worek F, Tattersall JEH. Bispyridinium Compounds Inhibit Both Muscle and Neuronal Nicotinic Acetylcholine Receptors in Human Cell Lines. PLoS One 2015; 10:e0135811. [PMID: 26274808 PMCID: PMC4537131 DOI: 10.1371/journal.pone.0135811] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 07/27/2015] [Indexed: 11/30/2022] Open
Abstract
Standard treatment of poisoning by organophosphorus anticholinesterases uses atropine to reduce the muscarinic effects of acetylcholine accumulation and oximes to reactivate acetylcholinesterase (the effectiveness of which depends on the specific anticholinesterase), but does not directly address the nicotinic effects of poisoning. Bispyridinium molecules which act as noncompetitive antagonists at nicotinic acetylcholine receptors have been identified as promising compounds and one has been shown to improve survival following organophosphorus poisoning in guinea-pigs. Here, we have investigated the structural requirements for antagonism and compared inhibitory potency of these compounds at muscle and neuronal nicotinic receptors and acetylcholinesterase. A series of compounds was synthesised, in which the length of the polymethylene linker between the two pyridinium moieties was increased sequentially from one to ten carbon atoms. Their effects on nicotinic receptor-mediated calcium responses were tested in muscle-derived (CN21) and neuronal (SH-SY5Y) cells. Their ability to inhibit acetylcholinesterase activity was tested using human erythrocyte ghosts. In both cell lines, the nicotinic response was inhibited in a dose-dependent manner and the inhibitory potency of the compounds increased with greater linker length between the two pyridinium moieties, as did their inhibitory potency for human acetylcholinesterase activity in vitro. These results demonstrate that bispyridinium compounds inhibit both neuronal and muscle nicotinic receptors and that their potency depends on the length of the hydrocarbon chain linking the two pyridinium moieties. Knowledge of structure-activity relationships will aid the optimisation of molecular structures for therapeutic use against the nicotinic effects of organophosphorus poisoning.
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Affiliation(s)
- Avi Ring
- Norwegian Defence Research Establishment, Kjeller, Norway
| | | | - Simon R. Turner
- Dstl Porton Down, Salisbury, Wiltshire, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | | | - Michael Bird
- Dstl Porton Down, Salisbury, Wiltshire, United Kingdom
| | | | - John E. Chad
- Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
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Karami-Mohajeri S, Nikfar S, Abdollahi M. A systematic review on the nerve–muscle electrophysiology in human organophosphorus pesticide exposure. Hum Exp Toxicol 2013; 33:92-102. [DOI: 10.1177/0960327113489047] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This article presents a systematic review of the recent literature on the scientific support of electromyography (EMG) and nerve conduction velocity (NCV) in diagnosing the exposure and toxicity of organophosphorus pesticides (OP). Specifically, this review focused on changes in EMG, NCV, occurrence of intermediate syndrome (IMS), and OP-induced delayed polyneuropathy (OPIDN) in human. All relevant bibliographic databases were searched for human studies using the key words “OP poisoning”, “electromyography”, “nerve conduction study,” and “muscles disorders”. IMS usually occurs after an acute cholinergic crisis, while OPIDN occurs after both acute and chronic exposures. Collection of these studies supports that IMS is a neuromuscular junction disorder and can be recorded upon the onset of respiratory failure. Due to heterogeneity of reports on outcomes of interest such as motor NCV and EMG amplitude in acute cases and inability to achieve precise estimation of effect in chronic cases meta-analysis was not helpful to this review. The OPIDN after both acute and low-level prolonged exposures develops peripheral neuropathy without preceding cholinergic toxicity and the progress of changes in EMG and NCV is parallel with the development of IMS and OPIDN. Persistent inhibition of acetylcholinesterase (AChE) is responsible for muscle weakness, but this is not the only factor involved in the incidence of this weakness in IMS or OPIDN suggestive of AChE assay not useful as an index of nerve and muscle impairment. Although several mechanisms for induction of this neurodegenerative disorder have been proposed as were reviewed for this article, among them oxidative stress and resulting apoptosis can be emphasized. Nevertheless, there is little synchronized evidence on subclinical electrophysiological findings that limit us to reach a strong conclusion on the diagnostic or prognostic use of EMG and NCV for acute and occupational exposures to OPs.
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Affiliation(s)
- S Karami-Mohajeri
- Department of Toxicology and Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran
| | - S Nikfar
- Department of Pharmacoeconomics and Pharmaceutical Administration, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran
- Food and Drug Laboratory Research Center, Food and Drug Organization, Tehran, Islamic Republic of Iran
| | - M Abdollahi
- Department of Toxicology and Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran
- Department of Pharmacoeconomics and Pharmaceutical Administration, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran
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Abstract
Descriptions of the South American arrow poisons known as curares were reported by explorers in the 16th century, and their site of action in producing neuromuscular block was determined by Claude Bernard in the mid-19th century. Tubocurarine, the most important curare alkaloid, played a large part in experiments to determine the role of acetylcholine in neuromuscular transmission, but it was not until after 1943 that neuromuscular blocking drugs became established as muscle relaxants for use during surgical anaesthesia. Tubocurarine causes a number of unwanted effects, and there have been many attempts to replace it. The available drugs fall into two main categories: the depolarising blocking drugs and the nondepolarising blocking drugs. The former act by complex mixed actions and are now obsolete with the exception of suxamethonium, the rapid onset and brief duration of action of which remain useful for intubation at the start of surgical anaesthesia. The nondepolarising blocking drugs are reversible acetylcholine receptor antagonists. The main ones are the atracurium group, which possess a built-in self-destruct mechanism that makes them specially useful in kidney or liver failure, and the vecuronium group, which are specially free from unwanted side effects. Of this latter group, the compound rocuronium is of special interest because its rapid onset of action allows it to be used for intubation, and there is promise that its duration of action may be rapidly terminated by a novel antagonist, a particular cyclodextrin, that chelates the drug, thereby removing it from the acetylcholine receptors.
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Affiliation(s)
- W C Bowman
- Department of Physiology and Pharmacology, University of Strathclyde, Glasgow G4 0NR.
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RANDIC M, STRAUGHAN DW. ANTIDROMIC ACTIVITY IN THE RAT PHRENIC NERVE-DIAPHRAGM PREPARATION. J Physiol 1996; 173:130-48. [PMID: 14205025 PMCID: PMC1368884 DOI: 10.1113/jphysiol.1964.sp007447] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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7
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BOWMAN WC, CALLINGHAM BA, CUTHBERT AW. THE EFFECTS OF PHYSOSTIGMINE ON THE MECHANICAL AND ELECTRICAL RESPONSES OF THE CAT NICTATING MEMBRANE. BRITISH JOURNAL OF PHARMACOLOGY AND CHEMOTHERAPY 1996; 22:558-76. [PMID: 14211686 PMCID: PMC1703932 DOI: 10.1111/j.1476-5381.1964.tb01710.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The effects of physostigmine on the electrical and mechanical responses of the nictitating membrane elicited by single nerve shocks have been studied in cats anaesthetized with a mixture of chloralose and pentobarbitone. The results were variable but the most consistent effect, observed with large doses of physostigmine, was a depression and prolongation of the contractions which was sometimes associated with augmentation of the characteristic rhythmic electrical activity of the smooth muscle. Although the amplitude of single responses was depressed, incomplete tetanic contractions were sometimes increased in tension because of the greater fusion which occurred as a result of prolongation of the units of contraction. Possible mechanisms underlying the effect of physostigmine are discussed.
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8
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Vizi ES. Evidence that catecholamines increase acetylcholine release from neuromuscular junction through stimulation of alpha-1 adrenoceptors. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1991; 343:435-8. [PMID: 1652696 DOI: 10.1007/bf00169543] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
1. The effects of alpha-1 adrenoceptor agonists on 3H-acetylcholine release from mouse phrenic nerve-hemidiaphragm preparation were studied. 2. In preparation which had been incubated with 3H-choline, electrical stimulation (50 Hz, 0.8 s trains every 10 s) released 3H-acetylcholine. Neurochemical evidence was obtained that noradrenaline, adrenaline and phenylephrine facilitated the stimulation evoked release of 3H-acetylcholine. This effect was much more marked when the prejunctional nicotinic receptors mediating positive feedback modulation were blocked by (+)-tubocurarine. In the presence of this drug, when the release of 3H-acetylcholine was reduced, alpha-1 adrenoceptor agonists enhanced the release in a prazosin-sensitive manner. 3. The rank order of potency of alpha-1 adrenoceptor agonists was adrenaline greater than noradrenaline greater than phenylephrine. By contrast, methoxamine had no effect on the release of 3H-acetylcholine. It is suggested, therefore, that circulating catecholamines may be able to affect neuromuscular transmission through stimulation of presynaptic alpha-1 adrenoceptors.
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Affiliation(s)
- E S Vizi
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest
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9
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Minker E, Blazso G. The effect of alkylating agents on the synaptic transmission in the frog's isolated sympathetic ganglion. Eur J Drug Metab Pharmacokinet 1987; 12:291-3. [PMID: 2835242 DOI: 10.1007/bf03189915] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The effect of four alkylating agents, such as dibenamine, phenoxybenzamine, mannomustine and cyclophosphamide, was studied on the isolated sympathetic ganglion of the frog. It has been established that all of these agents were able to bind to the nicotinic receptors through the formation of the reactive ethylenimonium ion not only in the frog ganglion but also in the motor end-plate of the rat skeletal muscle. The binding to the ganglionic receptors showed reversible and irreversible phases being dependent not only on the drug concentrations and the incubation time used but the temperature of the medium as well.
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Affiliation(s)
- E Minker
- Institute of Pharmacodynamics, University Medical School, Szeged, Hungary
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10
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Clark AL, Hobbiger F, Terrar DA. The effect of dithiothreitol on anticholinesterase induced antidromic firing and twitch potentiation [proceedings]. Br J Pharmacol 1979; 67:481P-482P. [PMID: 497592 PMCID: PMC2043984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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11
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Marshall RJ, Ojewole JA. Comparison of the autonomic effects of some currently-used neuromuscular blocking agents [proceedings]. Br J Pharmacol 1979; 66:77P-78P. [PMID: 454962 PMCID: PMC2043823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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12
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Abstract
1. The effects of edrophonium have been observed in the transversely cut tenuissimus muscle of the cat.2. Concentrations of edrophonium 10(-7)M to 10(-5)M increased the amplitude of the end-plate potential (e.p.p.) but produced no greater increase in time course than previously observed in curarized muscle.3. When the e.p.p. and gross nerve action potential were recorded simultaneously, antidromic discharges were observed in the motor nerve concomitantly with repetitive e.p.ps in the presence of edrophonium.4. Edrophonium produced no effect on the input resistance or equilibrium potential of the end-plate.5. The fractional release of transmitter was significantly increased by edrophonium but there was no increase in the quantal release of transmitter in the transversely cut muscle preparation.6. In curarized muscle edrophonium also increased the quantal release, the size of the available store of transmitter and the rate of refilling of the available store.7. It is concluded that edrophonium facilitates transmission to skeletal muscle by inducing a repetitive antidromic discharge in the nerve, following orthodromic stimulation. The antidromic discharge propagates by axon reflex to other nerve terminals of the same motor unit producing repetitive e.p.ps. It is also suggested that edrophonium antagonizes tubocurarine by acting as a partial agonist at the motor nerve terminal.
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13
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Ginsburg S, Kitz RJ, Savarese JJ. Neuromuscular blocking activity of a new series of quaternary N-substituted choline esters. Br J Pharmacol 1971; 43:107-26. [PMID: 4257628 PMCID: PMC1665940 DOI: 10.1111/j.1476-5381.1971.tb07161.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
1. The neuromuscular blocking activity of a new group of mono- and diquaternary N-substituted choline esters of several carboxylic acids has been evaluated in various whole animal preparations in the mouse, rat and cat.2. A basic non-depolarizing mechanism was present in all but one compound-a depolarizing agent, which was studied for comparison. There was evidence of facilitatory activity and nicotinic stimulation in the monoquaternary compounds. These effects were diminished in the diquaternary compounds.3. The presence of a bulky aromatic ring system on the nitrogen atom appeared to increase both neuromuscular blocking potency and facilitatory activity in the experimental animal. A similar relationship had previously been demonstrated in vitro in another study.4. The duration of action, although short in most compounds, did not correlate well with previously determined in vitro hydrolysis rates, possibly because of species differences.5. The general pharmacology of each compound appeared to depend considerably upon the structure of the choline moiety.
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Bowman WC, Goldberg AA, Raper C. Post-tetanic and drug-induced repetitive firing in the soleus muscle of the cat. Br J Pharmacol 1969; 35:62-78. [PMID: 4302727 PMCID: PMC1703081 DOI: 10.1111/j.1476-5381.1969.tb07967.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
1. The effects of a high frequency indirect tetanus on the responses to subsequent infrequently applied nerve shocks have been compared in the tibialis anterior and soleus muscles of cats and rabbits.2. Post-tetanic augmentation of twitches in the cat soleus muscle was shown to be partly due to repetitive firing and partly due to increased synchronization of the muscle fibre response. Post-tetanic repetitive firing was not evident in the responses of the other three muscles studied.3. Post-tetanic repetitive responses in the cat soleus muscle and nerve did not originate in the nerve trunk and were not produced by direct muscle stimulation; they were abolished by doses of tubocurarine smaller than those necessary to reduce the twitch tension below the pre-tetanic level. These findings support the conclusion of others that the repetitive firing originates at the neuromuscular junction.4. The repetitive firing could not be explained by an increase in the sensitivity of the motor endplates to acetylcholine, suggesting that an increase in and/or a prolongation of the output of transmitter from the motor nerve contributes to it.5. The cat soleus muscle was shown to be more sensitive to neostigmine than were the other three muscles studied, and acetylcholinesterase determinations showed that this muscle possesses less enzyme activity.6. It is concluded that an increase in transmitter output, coupled with a weaker cholinesterase activity, probably accounts for the post-tetanic repetitive activity in the cat soleus muscle.7. Post-tetanic repetitive firing was absent in cat soleus muscles which had been cross-innervated with the nerve formerly innervating a fast-contracting muscle.
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16
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Blaber LC, Goode JW. A comparison of the action of facilitatory and depolarizing drugs at the mammalian motor nerve terminal. INTERNATIONAL JOURNAL OF NEUROPHARMACOLOGY 1968; 7:429-40. [PMID: 5731756 DOI: 10.1016/0028-3908(68)90042-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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17
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Buckett WR, Marjoribanks CE, Marwick FA, Morton MB. The pharmacology of pancuronium bromide (Org.NA97), a new potent steroidal neuromuscular blocking agent. BRITISH JOURNAL OF PHARMACOLOGY AND CHEMOTHERAPY 1968; 32:671-82. [PMID: 4171017 PMCID: PMC1570332 DOI: 10.1111/j.1476-5381.1968.tb00466.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Pleuvry BJ, Hunter AR. A quantitative comparison of the antagonism of tubocurarine and diallylnortoxiferine by four anticurare agents. J Pharm Pharmacol 1967; 19:714-9. [PMID: 4383692 DOI: 10.1111/j.2042-7158.1967.tb08022.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Abstract
The antagonism of tubocurarine and diallylnortoxiferine by neostigmine, physostigmine, edrophonium and ambenonium, has been examined on the rat phrenic nerve diaphragm preparation. Ambenonium showed the greatest activity and physostigmine and edrophonium were the least potent and equally active. This order applied to both neuromuscular blocking agents, but all four antagonists show significantly greater activity against diallylnortoxiferine. The possibility that neostigmine and physostigmine have some qualitative differences in anticurare mechanism compared with edrophonium and ambenonium, on this preparation, is discussed.
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Blaber LC, Christ DD. The action of facilitatory drugs on the isolated tenuissimus muscle of the cat. INTERNATIONAL JOURNAL OF NEUROPHARMACOLOGY 1967; 6:473-84. [PMID: 5586668 DOI: 10.1016/0028-3908(67)90047-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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20
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Hubbard JI, Schmidt RF, Yokota T. The effect of acetylcholine upon mammalian motor nerve terminals. J Physiol 1965; 181:810-29. [PMID: 5881256 PMCID: PMC1357685 DOI: 10.1113/jphysiol.1965.sp007799] [Citation(s) in RCA: 117] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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