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Brown KA, Filipov NM, Wagner JJ. Dorsoventral-Specific Effects of Nerve Agent Surrogate Diisopropylfluorophosphate on Synaptic Transmission in the Mouse Hippocampus. J Pharmacol Exp Ther 2020; 373:10-23. [DOI: 10.1124/jpet.119.263053] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 12/16/2019] [Indexed: 11/22/2022] Open
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Sobolev VE, Shmurak VI, Goncharov NV. The Rat (Rattus norvegicus) as a Model Object for Acute Organophosphate Poisoning. 4. M1-Cholinoreceptors and Esterase Activity in Brain Homogenates. J EVOL BIOCHEM PHYS+ 2019. [DOI: 10.1134/s0022093019030116] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Hashjin GS, Dizaj FS, Attaran H, Koohi MK. Malathion induces anxiety in the male adult mouse. Arch Med Sci 2013; 9:368-71. [PMID: 23671451 PMCID: PMC3648820 DOI: 10.5114/aoms.2013.33174] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 09/15/2011] [Accepted: 12/08/2011] [Indexed: 11/30/2022] Open
Abstract
INTRODUCTION The cholinergic nervous system and acetylcholine esterase are involved in chronic intoxication with organophosphorous insecticides. The present study aims to investigate the influence of the chronic toxicity of these chemicals on behaviors related to anxiety, using the elevated plus maze (EPM), in the male adult mouse. MATERIAL AND METHODS Either water or 1% concentration of malathion was applied dermally to the male adult mice (10 s, once daily for 28 days) and, on day 29, the EPM test was done. RESULTS Time spent in the open arms (TSOA) in intoxicated animals was decreased by over 50% compared to the controls (p = 0.047). In contrast, time spent in closed arms was significantly higher in the malathion-exposed mice (p = 0.025). Percentage of open arm entries (OAE) was slightly smaller in the malathion-treated group in comparison to the control animals. Percentage of closed arm entries (CAE) in the treated group was slightly higher than the value in the control animals. CONCLUSIONS The results showed that chronic toxicity of malathion may lead to an anxiety-like behavior in the animal model used in this study. It is difficult to extend these findings to clinical situations. However, more experimental work in different animal species as well as epidemiological studies in human subjects in this regard are highly recommended.
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Affiliation(s)
| | - Farhad Sadeghi Dizaj
- Faculty of Veterinary Medicine, Islamic Azad University – Tabriz Campus, Tabriz, Iran
| | - Hadi Attaran
- Faculty of Veterinary Medicine, Islamic Azad University – Tabriz Campus, Tabriz, Iran
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Brain regional acetylcholinesterase activity and muscarinic acetylcholine receptors in rats after repeated administration of cholinesterase inhibitors and its withdrawal. Toxicol Appl Pharmacol 2007; 219:151-61. [DOI: 10.1016/j.taap.2006.11.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Revised: 11/04/2006] [Accepted: 11/06/2006] [Indexed: 11/18/2022]
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Deurveilher S, Delamanche IS, Hars B, Breton P, Hennevin E. Chronic, low-level exposure to the cholinesterase inhibitor DFP. I. Time course of neurochemical changes in the rat pontomesencephalic tegmentum. Pharmacol Biochem Behav 1999; 64:95-103. [PMID: 10495003 DOI: 10.1016/s0091-3057(99)00069-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Rats were repeatedly administered with a low dose of diisopropylfluorosphosphate (DFP; 0.2 mg/kg/day, SC, for 9 or 21 days), an irreversible cholinesterase (ChE) inhibitor. Control rats received a daily injection of oil vehicle. Neurochemical changes occurring in the pontomesencephalic tegmentum (PMT), a brain stem region critically involved in behavioral state control, were evaluated at various times of treatment and after DFP withdrawal. First, enzyme assay revealed a profile of ChE inhibition in the whole PMT which looked like that observed in the striatum; both the inhibition and recovery proceeded more slowly than they did in the plasma. Second, quantitative histochemistry indicated that ChE activity in the mesopontine cholinergic nuclei and the pontine reticular formation progressively decreased across the first days of DFP exposure, to reach an asymptotic level of inhibition after 6 days (74-82% inhibition). The inhibition was less pronounced in the locus coeruleus (49%). Third, [3H]QNB autoradiography showed that muscarinic receptor density was unchanged in any of the PMT areas selected. These results are discussed regarding the question of regional variation in susceptibility to anti-ChE agents. To what extent behavioral state alterations occur concomitantly with ChE activity changes is assessed in the companion article.
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Affiliation(s)
- S Deurveilher
- Laboratoire de Neurobiologie de l'Apprentissage et de la Mémoire, URA CNRS 1491, Université Paris-Sud, Orsay, France
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Jones SB, King LB, Sappington LC, Dwyer FJ, Ellersieck M, Buckler DR. Effects of carbaryl, permethrin, 4-nonylphenol, and copper on muscarinic cholinergic receptors in brain of surrogate and listed fish species. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART C, PHARMACOLOGY, TOXICOLOGY & ENDOCRINOLOGY 1998; 120:405-14. [PMID: 9827057 DOI: 10.1016/s0742-8413(98)10014-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We investigated the regulation of the muscarinic cholinergic receptor (MChR) in brain from seven species of fish, two surrogates and five threatened or endangered species exposed to a series of chemicals as a measure of compensatory response among species. Fish were classified as either cold water (rainbow trout-surrogate, apache trout, lahanton trout) or warm water (fathead minnow-surrogate, razorback sucker, bonytail chub, colorado squawfish) and were exposed to chemicals shown to affect cholinergic pathways (carbaryl and permethrin) and two chemicals whose relationships to the cholinergic system is less clear (4-nonylphenol and copper). Downregulation of MChR occurred in all warm water species, except colorado squawfish, and at carbaryl concentrations similar to those causing downregulation observed in rainbow trout. Permethrin exposure resulted in downregulation in fathead minnow and razorback sucker, but the concentrations required for observation of this phenomenon were much greater than observed in cold water species. Copper exposure caused a decrease in brain MChR in rainbow trout and apache trout, whereas 4-nonylphenol exposure resulted in a decrease in brain MChR in all three cold water species. Our results indicate that surrogates are useful in assessing sublethal physiological responses to chemicals with a known mechanism of action such as carbaryl and support use of surrogates for assessing physiological responses to chemicals with diverse, less clear mechanisms of action.
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Affiliation(s)
- S B Jones
- Environmental and Contaminants Research Center, USGS/Biological Resources Division, Columbia, MO 65201, USA.
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Abstract
The present study was carried out to assess the biochemical and behavioral sequelae of chronic dichlorvos (6 mg/kg b.wt/day for 8 weeks) exposure in rats. Dichlorvos administration significantly decreased the activities of neuropathy target esterase and other carboxylesterase viz., paraoxon resistant and mipafox and paraoxon resistant esterases. The acetylcholinesterase activity was also appreciably decreased following dichlorvos exposure. The alterations in biochemical parameters were also reflected in the behavioral patterns of dichlorvos-treated animals. Dichlorvos administration caused a marked decrease in both the ambulatory and stereotypic components of spontaneous locomotor activity of rats. The muscle strength and coordination of the dichlorvos-treated animals was also significantly impaired. Besides, a marked deterioration in the memory function assessed in terms of the conditioned avoidance response was discernible at the end of the treatment schedule in the experimental animals.
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Affiliation(s)
- S Sarin
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Ratnakumari L, Qureshi IA, Butterworth RF. Central muscarinic cholinergic M1 and M2 receptor changes in congenital ornithine transcarbamylase deficiency. Pediatr Res 1996; 40:25-8. [PMID: 8798241 DOI: 10.1203/00006450-199607000-00005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Congenital ornithine transcarbamylase (OTC) deficiency results in neuropathologic damage to the cerebral cortex, basal ganglia, and thalamus. However, the precise nature of the cell loss, as well as the pathophysiologic mechanisms responsible for it, have not been fully elucidated. In the present study, densities of the M1 and M2 subclasses of muscarinic cholinergic binding sites were assessed using quantitative receptor autoradiography in the brains of sparse-fur (spf) mice with congenital OTC deficiency and in age-matched CD-1 controls. Densities of binding sites for the muscarinic M1 subtype ligand [3H]pirenzepine were reduced by 24-54% (p < 0.01) in frontal cortex, caudate/ putamen, and hippocampal CA1 and CA2 areas. Since muscarinic M1 sites are localized presynaptically, their selective loss, together with a previous report of reduced activities of the presynaptic cholinergic enzyme choline acetyltransferase, confirms that loss of cholinergic neurons is an important feature of congenital OTC deficiency. Densities of binding sites for the predominantly postsynaptic muscarinic M2 subtype ligand 3H-AFDX 384 were increased by up to 60% (p < 0.01) in cerebral cortex, hippocampus, globus pallidus, as well as thalamic and hypothalamic structures of OTC-deficient mice. Increased M2 sites in the cerebral cortex, hippocampus, and thalamus are most likely the result of up-regulation of these sites after the loss of the presynaptic neuron. These findings support the presence of a central muscarinic cholinergic lesion in congenital OTC deficiency.
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Affiliation(s)
- L Ratnakumari
- Department of Medical Genetics, Hôpital Sainte-Justine, Montreal, Quebec, Canada
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Tan XX, Costa LG. Postnatal development of muscarinic receptor-stimulated phosphoinositide metabolism in mouse cerebral cortex: sensitivity to ethanol. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1995; 86:348-53. [PMID: 7656428 DOI: 10.1016/0165-3806(95)00024-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
An enhanced coupling of cholinergic muscarinic receptors to phosphoinositide metabolism had been previously observed in brain from immature rat. This study reports that the postnatal development of muscarinic receptor-stimulated phosphoinositide metabolism is also enhanced in cerebral cortex slices from immature Swiss-Webster and Balb-c mice, as compared to adults. Response to the agonist carbachol was lower on postnatal day 3, peaked between days 5 and 12 and then declined to adult levels. Density of muscarinic binding sites, measured with the M1 ligand [3H]telenzepine on postnatal day 7, was, on the other hand, only half of the adult value. Phosphoinositide hydrolysis stimulated by glutamate decreased with age, while that elicited by norepinephrine increased. These results are also similar to those previously reported in the rat. Ethanol has been found to inhibit muscarinic receptor-stimulated phosphoinositide metabolism in rat brain in an age-dependent manner. This was confirmed in mouse brain, where ethanol inhibited this response in cerebral cortex of immature but not adult animals. These results indicate that the enhanced muscarinic receptor-stimulated phosphoinositide metabolism, which coincides with the brain growth spurt, is similar in rats and mice. Mice may be a useful species in which to genetically manipulate muscarinic receptors to gain a better understanding of their potential role in brain development.
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Affiliation(s)
- X X Tan
- Department of Environmental Health, University of Washington, Seattle, USA
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Ehrich M, Intropido L, Costa LG. Interaction of organophosphorus compounds with muscarinic receptors in SH-SY5Y human neuroblastoma cells. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 1994; 43:51-63. [PMID: 8078092 DOI: 10.1080/15287399409531903] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Human neuroblastoma cells (line SH-SY5Y) were used to examine the interaction of single exposure to organophosphorus compounds (OPs) with muscarinic receptors. In this study, SH-SY5Y cells were exposed for 30 min to concentrations of paraoxon, diisopropyl phosphorofluoridate (DFP), phenyl saligenin cyclic phosphate (PSP), and mipafox (N,N'-diisopropyl phosphorodiamide fluoridate) that ranged between 10(-9) M and 10(-3) M (10(-2) M for mipafox). Ability to interfere with muscarinic receptor binding was determined by change in the binding of the nonspecific antagonist [3H]-N-methylscopolamine (3H-NMS). Concentrations of paraoxon > 0.5 x 10(-3) M and PSP 1 x 10(-3) M significantly inhibited the binding of a saturating concentration of 3H-NMS. Concentrations of > 10(-5) M paraoxon or PSP could significantly inhibit the binding of a half-saturating concentration of 3H-NMS. Studies using specific antagonists for muscarinic subtypes (pirenzepine for M1, AFDX-116 for M2, and 4-DAMP for M3) indicated that SH-SY5Y cells have muscarinic receptors most sensitive to the specific antagonist for the M3 subtype (IC50 of 10(-8) M for 4-DAMP compared to 2.5 x 10(-6) M and 2.7 x 10(-5) M for pirenzepine and AFDX-116, respectively). As M3 receptor stimulation results in formation of inositol phosphates from membrane phosphoinositides the capability of OPs to alter levels of inositol phosphates and agonist-stimulated increases in inositol phosphate formation was examined. Intact cells were prelabeled with [3H]myo-inositol and then incubated for 15 min with the OPs before addition of 10(-5) M to 10(-3) M carbachol. Levels of inositol phosphates were determined as the amount of aqueous soluble radiolabeled product extracted from the reaction mixture. Paraoxon and PSP, but not mipafox or DFP, decreased basal levels of inositol phosphates in a concentration-related manner. This could be overcome in cells stimulated with carbachol, a muscarinic agonist, and with sodium fluoride, which does not act at muscarinic receptors. These results indicate that certain OPs, upon acute exposure, interact with muscarinic receptors, but that they also have effects on levels of inositol phosphates that may be associated with another site of action in SH-SY5Y cells.
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Affiliation(s)
- M Ehrich
- Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg 24061-0442
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Jett DA, Fernando JC, Eldefrawi ME, Eldefrawi AT. Differential regulation of muscarinic receptor subtypes in rat brain regions by repeated injections of parathion. Toxicol Lett 1994; 73:33-41. [PMID: 8042201 DOI: 10.1016/0378-4274(94)90186-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Repeated injections with increasing moderate doses of parathion into adult male rats for 21 days resulted in 84-90% inhibition of acetylcholinesterase in the brain without overt signs of toxicity. Muscarinic acetylcholine receptor (mAChR) affinities for ligands were unaffected, but there was significant down-regulation of the m4 receptor subtype gene product, m1 mRNA and m3 mRNA in the frontal cortex as well as the m4 subtype and m4 mRNA in the striatum. However, in the hippocampus, there were no significant reductions in either the m1 receptor subtype nor its mRNA. The data suggest that the receptor subtype down-regulations in the cortex and striatum are due to reductions in mRNA expression. Since the degrees of inhibition of acetylcholinesterase were similar in the 3 brain regions, it is suggested that the in situ concentrations of paraoxon were also similar. Accordingly, the absence of down-regulation of the m1 receptor in the hippocampus is not due to a lower concentration of paraoxon than in the cortex or striatum. It is possible that injections of higher parathion doses would produce down-regulation of mAChRs in the hippocampus, and that the hippocampus may have differences in the feed-back mechanisms for receptor regulation from those in the frontal cortex and the striatum.
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Affiliation(s)
- D A Jett
- Department of Pharmacology and Experimental Therapeutics, University of Maryland, School of Medicine, Baltimore
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Tan XX, Costa LG. Inhibition of muscarinic receptor-stimulated phosphoinositide metabolism by cocaine, norcocaine and cocaethylene in rat brain. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1994; 79:132-5. [PMID: 8070057 DOI: 10.1016/0165-3806(94)90057-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The interaction of cocaine, its metabolites norcocaine and benzoylecgonine, and cocaethylene, which is formed following a combined cocaine and ethanol exposure, with muscarinic receptor binding and phosphoinositide metabolism was investigated in brain from immature rats. Cocaine and norcocaine inhibited binding of [3H]telenzepine and carbachol-stimulated phosphoinositide metabolism in cerebral cortex, while benzoylecgonine was devoid of any inhibitory activity. Cocaethylene was the most potent inhibitor of both binding and phosphoinositide metabolism. The effect of cocaine was more pronounced at the muscarinic receptors, but a small inhibition of histamine--and serotonin--stimulated phosphoinositide metabolism was also observed.
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Affiliation(s)
- X X Tan
- Department of Environmental Health, University of Washington, Seattle 98195
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