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Macedo MB, Cunha EO, Reis AD, Machado MS, de Campos D, Malysz T, Dallegrave E. Morphometric Evaluation of the Recurrent Laryngeal Nerve of Wistar Rats Exposed to Pesticides. J Voice 2024; 38:264-272. [PMID: 34782225 DOI: 10.1016/j.jvoice.2021.09.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/09/2021] [Accepted: 09/23/2021] [Indexed: 10/19/2022]
Abstract
The literature has been shown that exposition by inhalation to chemical compounds can cause vocal disorders and dysphagia in humans, in addition to other symptoms that are manifested according to the type, concentration and duration of exposure to the substance. Cypermethrin and dichlorvos are pesticides widely used in agriculture, public health, veterinary, and home environments. Despite the scientific evidence that cypermethrin and dichlorvos can cause neurodegenerative damage and motor alterations, there are no studies evaluating the toxic effects of these pesticides on the morphology of structures responsible for vocal mobility, especially to the Recurrent Laryngeal Nerve (RLN). Considering the association between vocal disorders in humans and variations in RLN and morphometry, the aim of this study was to evaluate the possible alterations in the microstructure of RLN secondary to subchronic exposure to cypermethrin (pyrethroid) and dichlorvos (organophosphate) in Wistar rats. The experimental protocol (approved by CEUA-UFCSPA: 321/15 and 323/15) consisted of 15 male Wistar rats, allocated in 3 groups: Control (n = 5, exposed to water), Cypermethrin (n = 5, exposed to cypermethrin - 1/10 of the inhalation median lethal concentration [LC50] - 0.25 mg/L) and dichlorvos (n = 5, exposed to dichlorvos - 1/10 of the LC50 - 1.5 mg/L). Inhalation exposure was performed for 4 hours, 5 times per week, for 6 weeks. The nerves were collected, histologically processed and analyzed using morphometric parameters measured using ZEN 2.6 (Zeiss - Germany). The cypermethrin and dichlorvos groups showed significant changes (P < 0.001, ANOVA) in the g-ratio and in the thickness of the myelin sheath of the RLN when compared to the control animals, however, none of the other parameters evaluated showed statistically significant differences. These findings indicate that repeated inhalation exposure to commercial products of cypermethrin and dichlorvos is able to modify the structure of the RLN and possibly generating vocal changes and / or dysphagia.
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Affiliation(s)
- Mateus Belmonte Macedo
- Graduate Program in Pathology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil; Laboratory of Research in Toxicology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil
| | - Eduarda Oliveira Cunha
- Graduate Program in Health Sciences, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil; Laboratory of Research in Toxicology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil
| | - Aléxia Dos Reis
- Graduate Program in Pathology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil; Laboratory of Research in Toxicology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil
| | - Márcia Salgado Machado
- Department of Speech Therapy and Audiology, University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil; Laboratory of Research in Toxicology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil
| | - Deivis de Campos
- Department of Basic Health Sciences, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil; Department of Life Sciences, University of Santa Cruz do Sul (UNISC), Santa Cruz do Sul, RS, Brazil; Graduate Program in Health Promotion, University of Santa Cruz do Sul (UNISC), Santa Cruz do Sul, RS, Brazil
| | - Taís Malysz
- Graduate Program in Neurosciences, Basic Health Sciences Institute, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Eliane Dallegrave
- Graduate Program in Pathology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil; Graduate Program in Health Sciences, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil; Department of Pharmacosciences, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil; Laboratory of Research in Toxicology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil.
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Combinations of classical and non-classical voltage dependent potassium channel openers suppress nociceptor discharge and reverse chronic pain signs in a rat model of Gulf War illness. Neurotoxicology 2022; 93:186-199. [PMID: 36216193 DOI: 10.1016/j.neuro.2022.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 09/27/2022] [Accepted: 10/05/2022] [Indexed: 11/15/2022]
Abstract
In a companion paper we examined whether combinations of Kv7 channel openers (Retigabine and Diclofenac; RET, DIC) could be effective modifiers of deep tissue nociceptor activity; and whether such combinations could then be optimized for use as safe analgesics for pain-like signs that developed in a rat model of GWI (Gulf War Illness) pain. In the present report, we examined the combinations of Retigabine/Meclofenamate (RET/MEC) and Meclofenamate/Diclofenac (MEC/DIC). Voltage clamp experiments were performed on deep tissue nociceptors isolated from rat DRG (dorsal root ganglion). In voltage clamp studies, a stepped voltage protocol was applied (-55 to -40 mV; Vh=-60 mV; 1500 msec) and Kv7 evoked currents were subsequently isolated by Linopirdine subtraction. MEC greatly enhanced voltage dependent conductance and produced exceptional maximum sustained currents of 6.01 ± 0.26 pA/pF (EC50: 62.2 ± 8.99 μM). Combinations of RET/MEC, and MEC/DIC substantially amplified resting currents at low concentrations. MEC/DIC also greatly improved voltage dependent conductance. In current clamp experiments, a cholinergic challenge test (Oxotremorine-M, 10 μM; OXO), associated with our GWI rat model, produced powerful action potential (AP) bursts (85 APs). Optimized combinations of RET/MEC (5 and 0.5 μM) and MEC/DIC (0.5 and 2.5 μM) significantly reduced AP discharges to 3 and 7 Aps, respectively. Treatment of pain-like ambulatory behavior in our rat model with a RET/MEC combination (5 and 0.5 mg/kg) successfully rescued ambulation deficits, but could not be fully separated from the effect of RET alone. Further development of this approach is recommended.
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Ireland D, Zhang S, Bochenek V, Hsieh JH, Rabeler C, Meyer Z, Collins EMS. Differences in neurotoxic outcomes of organophosphorus pesticides revealed via multi-dimensional screening in adult and regenerating planarians. FRONTIERS IN TOXICOLOGY 2022; 4:948455. [PMID: 36267428 PMCID: PMC9578561 DOI: 10.3389/ftox.2022.948455] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 08/25/2022] [Indexed: 11/07/2022] Open
Abstract
Organophosphorus pesticides (OPs) are a chemically diverse class of commonly used insecticides. Epidemiological studies suggest that low dose chronic prenatal and infant exposures can lead to life-long neurological damage and behavioral disorders. While inhibition of acetylcholinesterase (AChE) is the shared mechanism of acute OP neurotoxicity, OP-induced developmental neurotoxicity (DNT) can occur independently and/or in the absence of significant AChE inhibition, implying that OPs affect alternative targets. Moreover, different OPs can cause different adverse outcomes, suggesting that different OPs act through different mechanisms. These findings emphasize the importance of comparative studies of OP toxicity. Freshwater planarians are an invertebrate system that uniquely allows for automated, rapid and inexpensive testing of adult and developing organisms in parallel to differentiate neurotoxicity from DNT. Effects found only in regenerating planarians would be indicative of DNT, whereas shared effects may represent neurotoxicity. We leverage this unique feature of planarians to investigate potential differential effects of OPs on the adult and developing brain by performing a comparative screen to test 7 OPs (acephate, chlorpyrifos, dichlorvos, diazinon, malathion, parathion and profenofos) across 10 concentrations in quarter-log steps. Neurotoxicity was evaluated using a wide range of quantitative morphological and behavioral readouts. AChE activity was measured using an Ellman assay. The toxicological profiles of the 7 OPs differed across the OPs and between adult and regenerating planarians. Toxicological profiles were not correlated with levels of AChE inhibition. Twenty-two "mechanistic control compounds" known to target pathways suggested in the literature to be affected by OPs (cholinergic neurotransmission, serotonin neurotransmission, endocannabinoid system, cytoskeleton, adenyl cyclase and oxidative stress) and 2 negative controls were also screened. When compared with the mechanistic control compounds, the phenotypic profiles of the different OPs separated into distinct clusters. The phenotypic profiles of adult vs. regenerating planarians exposed to the OPs clustered differently, suggesting some developmental-specific mechanisms. These results further support findings in other systems that OPs cause different adverse outcomes in the (developing) brain and build the foundation for future comparative studies focused on delineating the mechanisms of OP neurotoxicity in planarians.
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Affiliation(s)
- Danielle Ireland
- Department of Biology, Swarthmore College, Swarthmore, PA, United States
| | - Siqi Zhang
- Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
| | - Veronica Bochenek
- Department of Biology, Swarthmore College, Swarthmore, PA, United States
| | - Jui-Hua Hsieh
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Christina Rabeler
- Department of Biology, Swarthmore College, Swarthmore, PA, United States
| | - Zane Meyer
- Department of Engineering, Swarthmore College, Swarthmore, PA, United States
- Department of Computer Science, Swarthmore College, Swarthmore, PA, United States
| | - Eva-Maria S. Collins
- Department of Biology, Swarthmore College, Swarthmore, PA, United States
- Department of Physics and Astronomy, Swarthmore College, Swarthmore, PA, United States
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Center of Excellence in Environmental Toxicology, University of Pennsylvania, Philadelphia, PA, United States
- Department of Physics, University of California San Diego, La Jolla, CA, United States
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Organophosphorus Pesticides as Modulating Substances of Inflammation through the Cholinergic Pathway. Int J Mol Sci 2022; 23:ijms23094523. [PMID: 35562914 PMCID: PMC9104626 DOI: 10.3390/ijms23094523] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/12/2022] [Accepted: 04/14/2022] [Indexed: 01/27/2023] Open
Abstract
Organophosphorus pesticides (OPs) are widespread insecticides used for pest control in agricultural activities and the control of the vectors of human and animal diseases. However, OPs’ neurotoxic mechanism involves cholinergic components, which, beyond being involved in the transmission of neuronal signals, also influence the activity of cytokines and other pro-inflammatory molecules; thus, acute and chronic exposure to OPs may be related to the development of chronic degenerative pathologies and other inflammatory diseases. The present article reviews and discusses the experimental evidence linking inflammatory process with OP-induced cholinergic dysregulation, emphasizing the molecular mechanisms related to the role of cytokines and cellular alterations in humans and other animal models, and possible therapeutic targets to inhibit inflammation.
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Development of KVO treatment strategies for chronic pain in a rat model of Gulf War Illness. Toxicol Appl Pharmacol 2022; 434:115821. [PMID: 34896435 DOI: 10.1016/j.taap.2021.115821] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/01/2021] [Accepted: 12/04/2021] [Indexed: 12/19/2022]
Abstract
We examined whether combinations of Kv7 channel openers could be effective modifiers of deep tissue nociceptor activity; and whether such combinations could then be optimized for use as safe analgesics for pain-like signs that developed in a rat model of GWI (Gulf War Illness) pain. Voltage clamp experiments were performed on subclassified nociceptors isolated from rat DRG (dorsal root ganglion). A stepped voltage protocol was applied (-55 to -40 mV; Vh = -60 mV; 1500 ms) and Kv7 evoked currents were subsequently isolated by linopirdine subtraction. Directly activated and voltage activated K+ currents were characterized in the presence and absence of Retigabine (5-100 μM) and/or Diclofenac (50-140 μM). Retigabine produced substantial voltage dependent effects and a maximal sustained current of 1.14 pA/pF ± 0.15 (ED50: 62.7 ± 3.18 μM). Diclofenac produced weak voltage dependent effects but a similar maximum sustained current of 1.01 ± 0.26 pA/pF (ED50: 93.2 ± 8.99 μM). Combinations of Retigabine and Diclofenac substantially amplified resting currents but had little effect on voltage dependence. Using a cholinergic challenge test (Oxotremorine, 10 μM) associated with our GWI rat model, combinations of Retigabine (5 uM) and Diclofenac (2.5, 20 and 50 μM) substantially reduced or totally abrogated action potential discharge to the cholinergic challenge. When combinations of Retigabine and Diclofenac were used to relieve pain-signs in our rat model of GWI, only those combinations associated with serious subacute side effects could relieve pain-like behaviors.
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Calco GN, Proskocil BJ, Jacoby DB, Fryer AD, Nie Z. Metformin prevents airway hyperreactivity in rats with dietary obesity. Am J Physiol Lung Cell Mol Physiol 2021; 321:L1105-L1118. [PMID: 34668415 DOI: 10.1152/ajplung.00202.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Increased insulin is associated with obesity-related airway hyperreactivity and asthma. We tested whether the use of metformin, an anti-diabetic drug used to reduce insulin resistance, can reduce circulating insulin, thereby preventing airway hyperreactivity in rats with dietary obesity. Male and female rats were fed a high- or low-fat diet for 5 weeks. Some male rats were simultaneously treated with metformin (100 mg/kg, p.o.). In separate experiments, after 5 weeks of a high-fat diet, some rats were switched to a low-fat diet, while others continued a high-fat diet for an additional 5 weeks. Bronchoconstriction and bradycardia in response to bilateral electrical vagus nerve stimulation or to inhaled methacholine were measured in anesthetized and vagotomized rats. Body weight, body fat, caloric intake, fasting glucose and insulin were measured. Vagally-induced bronchoconstriction was potentiated only in male rats on a high-fat diet. Males gained more body weight, body fat, and had increased levels of fasting insulin, compared to females. Metformin prevented development of vagally-induced airway hyperreactivity in male rats on high-fat diet, in addition to inhibiting weight gain, fat gain and increased insulin. In contrast, switching rats to a low-fat diet for 5 weeks reduced body weight and body fat, it did not reverse fasting glucose, fasting insulin or potentiation of vagally-induced airway hyperreactivity. These data suggest that medications that target insulin may be effective treatment for obesity-related asthma.
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Affiliation(s)
- Gina N Calco
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon, United States
| | - Becky J Proskocil
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon, United States
| | - David B Jacoby
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon, United States
| | - Allison D Fryer
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon, United States
| | - Zhenying Nie
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon, United States
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Proskocil BJ, Fryer AD, Jacoby DB, Nie Z. Pioglitazone prevents obesity-related airway hyperreactivity and neuronal M 2 receptor dysfunction. Am J Physiol Lung Cell Mol Physiol 2021; 321:L236-L247. [PMID: 34009030 PMCID: PMC8321847 DOI: 10.1152/ajplung.00567.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 04/26/2021] [Accepted: 05/12/2021] [Indexed: 11/22/2022] Open
Abstract
Obesity-related asthma often presents with more severe symptoms than non-obesity-related asthma and responds poorly to current treatments. Both insulin resistance and hyperinsulinemia are common in obesity. We have shown that increased insulin mediates airway hyperreactivity in diet-induced obese rats by causing neuronal M2 muscarinic receptor dysfunction, which normally inhibits acetylcholine release from parasympathetic nerves. Decreasing insulin with streptozotocin prevented airway hyperreactivity and M2 receptor dysfunction. The objective of the present study was to investigate whether pioglitazone, a hypoglycemic drug, prevents airway hyperreactivity and M2 receptor dysfunction in obese rats. Male rats fed a low- or high-fat diet were treated with pioglitazone or PBS by daily gavage. Body weight, body fat, fasting insulin, and bronchoconstriction and bradycardia in response to electrical stimulation of vagus nerves and to aerosolized methacholine were recorded. Pilocarpine, a muscarinic receptor agonist, was used to measure M2 receptor function. Rats on a high-fat diet had potentiated airway responsiveness to vagal stimulation and dysfunctional neuronal M2 receptors, whereas airway responsiveness to methacholine was unaffected. Pioglitazone reduced fasting insulin and prevented airway hyperresponsiveness and M2 receptor dysfunction but did not change inflammatory cytokine mRNA expression in alveolar macrophages. High-fat diet, with and without pioglitazone, had tissue-specific effects on insulin receptor mRNA expression. In conclusion, pioglitazone prevents vagally mediated airway hyperreactivity and protects neuronal M2 muscarinic receptor function in obese rats.
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Affiliation(s)
- Becky J Proskocil
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon
| | - Allison D Fryer
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon
| | - David B Jacoby
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon
| | - Zhenying Nie
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon
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Pulmonary toxicity associated with occupational and environmental exposure to pesticides and herbicides. Curr Opin Pulm Med 2021; 27:278-283. [PMID: 33882510 DOI: 10.1097/mcp.0000000000000777] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
PURPOSE OF REVIEW Critical review on the notion that exposure to pesticides and herbicides lead to adverse effects in pulmonary health. RECENT FINDINGS The lung effects of several chemical classes of pesticides and herbicides is biologically plausible. However, the studies that describe the association between exposure and toxic lung effects have numerous limitations. Critical evaluation of the studies that are performed shows that assessment of occupational or environmental exposure to pesticides and herbicides is cumbersome. Moreover, the health effects are not always clearly established due to the use of questionnaires and self-reported data instead of lung function measurements or diagnostic work-up by physicians.Future studies should preferably better characterize the exposure. Genetic phenotyping should be included to understand and strengthen possible (individual) associations between exposure and health outcome. It should be realized that combined exposure to multiple environmental chemicals may lead to different health effects than exposure to individual chemicals. SUMMARY The relation between exposure to pesticides and herbicides and lung toxicity is less clear than generally assumed. Adverse lung effects seem multifactorial and needs further research. Preventive measures remain key.
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Monitoring of the Organophosphate Pesticide Chlorpyrifos in Vegetable Samples from Local Markets in Northern Thailand by Developed Immunoassay. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17134723. [PMID: 32630084 PMCID: PMC7369984 DOI: 10.3390/ijerph17134723] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 06/24/2020] [Accepted: 06/25/2020] [Indexed: 11/25/2022]
Abstract
Chlorpyrifos is an organophosphate pesticide that is wildly used among farmers for crop protection. However, there are concerns regarding its contamination in the environment and food chain. In the present study, an in-house indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) specific for detecting chlorpyrifos is developed and validated against gas chromatography–flame photometric detection (GC-FPD) as the conventional method. The developed ic-ELISA was used for detecting chlorpyrifos residue in vegetable samples. The developed ic-ELISA showed good sensitivity to chlorpyrifos at an IC50 of 0.80 µg/kg, with low cross-reactivity to other organophosphate pesticides. The 160 samples were collected from local markets located in the Chiang Rai, Chiang Mai, and Nan provinces in northern Thailand. The positive rate of chlorpyrifos residues in the vegetable samples was 33.8%, with the highest levels found in cucumbers, coriander, and morning glory, at 275, 145, and 35.3 µg/kg, respectively. The highest median levels of chlorpyrifos found in the detected samples were Chinese cabbage (332 μg/kg), cucumber (146.3 μg/kg) and Chinese Kale (26.95 μg/kg). The developed ic-ELISA is suitable for the rapid quantitation of chlorpyrifos residues.
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Proskocil BJ, Grodzki ACG, Jacoby DB, Lein PJ, Fryer AD. Organophosphorus Pesticides Induce Cytokine Release from Differentiated Human THP1 Cells. Am J Respir Cell Mol Biol 2020; 61:620-630. [PMID: 30978295 DOI: 10.1165/rcmb.2018-0257oc] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Epidemiologic studies link organophosphorus pesticides (OPs) to increased incidence of asthma. In guinea pigs, OP-induced airway hyperreactivity requires macrophages and TNF-α. Here, we determined whether OPs interact directly with macrophages to alter cytokine expression or release. Human THP1 cells were differentiated into macrophages and then exposed to parathion, chlorpyrifos, or diazinon, or their oxon, phosphate, or phosphorothioate metabolites for 24 hours in the absence or presence of reagents that block cholinergic receptors. TNF-α, IL-1β, platelet-derived growth factor, and transforming growth factor-β mRNA and protein were quantified by qPCR and ELISA, respectively. The effects of OPs on NF-κB, acetylcholinesterase, and intracellular calcium were also measured. Parent OPs and their oxon metabolites upregulated cytokine mRNA and stimulated cytokine release. TNF-α release, which was the most robust response, was triggered by parent, but not oxon, compounds. Cytokine expression was also increased by diethyl dithiophosphate but not diethyl thiophosphate or diethyl phosphate metabolites. Parent OPs, but not oxon metabolites, activated NF-κB. Parent and oxon metabolites decreased acetylcholinesterase activity, but comparable acetylcholinesterase inhibition by eserine did not mimic OP effects on cytokines. Consistent with the noncholinergic mechanisms of OP effects on macrophages, pharmacologic antagonism of muscarinic or nicotinic receptors did not prevent OP-induced cytokine expression or release. These data indicate that phosphorothioate OP compounds directly stimulate macrophages to release TNF-α, potentially via activation of NF-κB, and suggest that therapies that target NF-κB may prevent OP-induced airway hyperreactivity.
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Affiliation(s)
- Becky J Proskocil
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon; and
| | - Ana Cristina G Grodzki
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, Davis, California
| | - David B Jacoby
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon; and
| | - Pamela J Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, Davis, California
| | - Allison D Fryer
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon; and
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El Khayat El Sabbouri H, Gay-Quéheillard J, Joumaa WH, Delanaud S, Guibourdenche M, Darwiche W, Djekkoun N, Bach V, Ramadan W. Does the perigestational exposure to chlorpyrifos and/or high-fat diet affect respiratory parameters and diaphragmatic muscle contractility in young rats? Food Chem Toxicol 2020; 140:111322. [PMID: 32289335 DOI: 10.1016/j.fct.2020.111322] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/17/2020] [Accepted: 04/03/2020] [Indexed: 02/08/2023]
Abstract
The perinatal period is characterized by developmental stages with high sensitivity to environmental factors. Among the risk factors, maternal High-Fat Diet (HFD) consumption and early-life pesticide exposure can induce metabolic disorders at adulthood. We established the effects of perigestational exposure to Chlorpyrifos (CPF) and/or HFD on respiratory parameters, sleep apnea and diaphragm contractility in adult rats. Four groups of female rats were exposed starting from 4 months before gestation till the end of lactation period to CPF (1 mg/kg/day vs. vehicle) with or without HFD. Sleep apnea and respiratory parameters were measured by whole-body plethysmography in male offspring at postnatal day 60. Then diaphragm strips were dissected for the measurement of contractility, acetylcholinesterase (AChE) activity, and gene expression. The perigestational exposure to CPF and/or HFD increased the sleep apnea index but decreased the respiratory frequency. The twitch tension and the fatigability index were also increased, associated with reduced AChE activity and elevated mRNA expression of AChE, ryanodine receptor, and myosin heavy chain isoforms. Therefore, the perigestational exposure to either CPF and/or HFD could program the risks for altered ventilatory parameters and diaphragm contractility in young adult offspring despite the lack of direct contact to CPF and/or HFD.
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Affiliation(s)
- Hiba El Khayat El Sabbouri
- PERITOX UMR-I-01 University of Picardie Jules Verne, 80025, Amiens, France; Laboratoire Rammal Hassan Rammal, équipe de Recherche PhyToxE, Faculté des Sciences (section V), Université Libanaise, Nabatieh, Lebanon
| | | | - Wissam H Joumaa
- Laboratoire Rammal Hassan Rammal, équipe de Recherche PhyToxE, Faculté des Sciences (section V), Université Libanaise, Nabatieh, Lebanon
| | - Stephane Delanaud
- PERITOX UMR-I-01 University of Picardie Jules Verne, 80025, Amiens, France
| | | | - Walaa Darwiche
- Hematim Laboratory, EA4666, University of Picardie Jules Verne, 80025, Amiens, France
| | - Narimane Djekkoun
- PERITOX UMR-I-01 University of Picardie Jules Verne, 80025, Amiens, France
| | - Véronique Bach
- PERITOX UMR-I-01 University of Picardie Jules Verne, 80025, Amiens, France
| | - Wiam Ramadan
- Laboratoire Rammal Hassan Rammal, équipe de Recherche PhyToxE, Faculté des Sciences (section V), Université Libanaise, Nabatieh, Lebanon; Lebanese Institute for Biomedical Research and Application (LIBRA), International University of Beirut (BIU) and Lebanese International University (LIU), Beirut, Lebanon
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12
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Shaffo FC, Grodzki AC, Fryer AD, Lein PJ. Mechanisms of organophosphorus pesticide toxicity in the context of airway hyperreactivity and asthma. Am J Physiol Lung Cell Mol Physiol 2018; 315:L485-L501. [PMID: 29952220 PMCID: PMC6230874 DOI: 10.1152/ajplung.00211.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/15/2018] [Accepted: 06/18/2018] [Indexed: 12/14/2022] Open
Abstract
Numerous epidemiologic studies have identified an association between occupational exposures to organophosphorus pesticides (OPs) and asthma or asthmatic symptoms in adults. Emerging epidemiologic data suggest that environmentally relevant levels of OPs may also be linked to respiratory dysfunction in the general population and that in utero and/or early life exposures to environmental OPs may increase risk for childhood asthma. In support of a causal link between OPs and asthma, experimental evidence demonstrates that occupationally and environmentally relevant OP exposures induce bronchospasm and airway hyperreactivity in preclinical models. Mechanistic studies have identified blockade of autoinhibitory M2 muscarinic receptors on parasympathetic nerves that innervate airway smooth muscle as one mechanism by which OPs induce airway hyperreactivity, but significant questions remain regarding the mechanism(s) by which OPs cause neuronal M2 receptor dysfunction and, more generally, how OPs cause persistent asthma, especially after developmental exposures. The goals of this review are to 1) summarize current understanding of OPs in asthma; 2) discuss mechanisms of OP neurotoxicity and immunotoxicity that warrant consideration in the context of OP-induced airway hyperreactivity and asthma, specifically, inflammatory responses, oxidative stress, neural plasticity, and neurogenic inflammation; and 3) identify critical data gaps that need to be addressed in order to better protect adults and children against the harmful respiratory effects of low-level OP exposures.
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Affiliation(s)
- Frances C Shaffo
- Department of Molecular Biosciences, University of California , Davis, California
| | - Ana Cristina Grodzki
- Department of Molecular Biosciences, University of California , Davis, California
| | - Allison D Fryer
- Pulmonary Critical Care Medicine, Department of Medicine, Oregon Health & Science University , Portland, Oregon
| | - Pamela J Lein
- Department of Molecular Biosciences, University of California , Davis, California
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Naughton SX, Terry AV. Neurotoxicity in acute and repeated organophosphate exposure. Toxicology 2018; 408:101-112. [PMID: 30144465 DOI: 10.1016/j.tox.2018.08.011] [Citation(s) in RCA: 160] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 08/03/2018] [Accepted: 08/21/2018] [Indexed: 01/28/2023]
Abstract
The term organophosphate (OP) refers to a diverse group of chemicals that are found in hundreds of products worldwide. As pesticides, their most common use, OPs are clearly beneficial for agricultural productivity and the control of deadly vector-borne illnesses. However, as a consequence of their widespread use, OPs are now among the most common synthetic chemicals detected in the environment as well as in animal and human tissues. This is an increasing environmental concern because many OPs are highly toxic and both accidental and intentional exposures to OPs resulting in deleterious health effects have been documented for decades. Some of these deleterious health effects include a variety of long-term neurological and psychiatric disturbances including impairments in attention, memory, and other domains of cognition. Moreover, some chronic illnesses that manifest these symptoms such as Gulf War Illness and Aerotoxic Syndrome have (at least in part) been attributed to OP exposure. In addition to acute acetylcholinesterase inhibition, OPs may affect a number of additional targets that lead to oxidative stress, axonal transport deficits, neuroinflammation, and autoimmunity. Some of these targets could be exploited for therapeutic purposes. The purpose of this review is thus to: 1) describe the important uses of organophosphate (OP)-based compounds worldwide, 2) provide an overview of the various risks and toxicology associated with OP exposure, particularly long-term neurologic and psychiatric symptoms, 3) discuss mechanisms of OP toxicity beyond cholinesterase inhibition, 4) review potential therapeutic strategies to reverse the acute toxicity and long term deleterious effects of OPs.
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Affiliation(s)
- Sean X Naughton
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, 30912, Georgia
| | - Alvin V Terry
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, 30912, Georgia.
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Drake MG, Lebold KM, Roth-Carter QR, Pincus AB, Blum ED, Proskocil BJ, Jacoby DB, Fryer AD, Nie Z. Eosinophil and airway nerve interactions in asthma. J Leukoc Biol 2018; 104:61-67. [PMID: 29633324 DOI: 10.1002/jlb.3mr1117-426r] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 02/07/2018] [Accepted: 02/07/2018] [Indexed: 12/19/2022] Open
Abstract
Airway eosinophils are increased in asthma and are especially abundant around airway nerves. Nerves control bronchoconstiction and in asthma, airway hyperreactivity (where airways contract excessively to inhaled stimuli) develops when eosinophils alter both parasympathetic and sensory nerve function. Eosinophils release major basic protein, which is an antagonist of inhibitory M2 muscarinic receptors on parasympathetic nerves. Loss of M2 receptor inhibition potentiates parasympathetic nerve-mediated bronchoconstriction. Eosinophils also increase sensory nerve responsiveness by lowering neurons' activation threshold, stimulating nerve growth, and altering neuropeptide expression. Since sensory nerves activate parasympathetic nerves via a central neuronal reflex, eosinophils' effects on both sensory and parasympathetic nerves potentiate bronchoconstriction. This review explores recent insights into mechanisms and effects of eosinophil and airway nerve interactions in asthma.
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Affiliation(s)
- Matthew G Drake
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon, USA
| | - Katherine M Lebold
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon, USA
| | - Quinn R Roth-Carter
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon, USA
| | - Alexandra B Pincus
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon, USA
| | - Emily D Blum
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon, USA
| | - Becky J Proskocil
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon, USA
| | - David B Jacoby
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon, USA
| | - Allison D Fryer
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon, USA
| | - Zhenying Nie
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, Oregon, USA
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Darwiche W, Gay-Quéheillard J, Delanaud S, El Khayat El Sabbouri H, Khachfe H, Joumaa W, Bach V, Ramadan W. Impact of chronic exposure to the pesticide chlorpyrifos on respiratory parameters and sleep apnea in juvenile and adult rats. PLoS One 2018; 13:e0191237. [PMID: 29357379 PMCID: PMC5777649 DOI: 10.1371/journal.pone.0191237] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 12/29/2017] [Indexed: 11/23/2022] Open
Abstract
The widely used organophosphorus pesticide chlorpyrifos (CPF) is often detected in food. CPF inhibits acetylcholinesterase and can modify muscle contractility and respiratory patterns. We studied the effects of chronic exposure to CPF on respiratory parameters and diaphragm contractility in 21- and 60-days old rats. Pregnant rats were exposed to oral CPF (1 or 5 mg/ kg /day: CPF-1 or CPF-5 groups vs vehicle: controls) from gestation onset up to weaning of the pups that were individually gavaged (CPF or vehicle) thereafter. Two developmental time points were studied: weaning (day 21) and adulthood (day 60). Whole-body plethysmography was used to score breathing patterns and apnea index during sleep. Then, diaphragm strips were dissected for the assessment of contractility and acetylcholinesterase activity. Results showed that the sleep apnea index was higher in CPF-exposed rats than in controls. In adult rats, the expiratory time and tidal volume were higher in CPF-exposed animals than in controls. At both ages, the diaphragm’s amplitude of contraction and fatigability index were higher in the CPF-5 group, due to lower acetylcholinesterase activity. We conclude that chronic exposure to CPF is associated with higher sleep apnea index and diaphragm contractility, and modifies respiratory patterns in sleeping juvenile and adult rats.
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Affiliation(s)
- Walaa Darwiche
- PériTox, Périnatalité & Risques Toxiques, UMR-I 01 INERIS, Amiens, France
- PhyToxE, Environmental Physio-Toxicity group, Rammal Hassan Rammal laboratory, Lebanese University, Faculty of Sciences, Nabatieh, Lebanon
- * E-mail:
| | | | - Stéphane Delanaud
- PériTox, Périnatalité & Risques Toxiques, UMR-I 01 INERIS, Amiens, France
| | - Hiba El Khayat El Sabbouri
- PériTox, Périnatalité & Risques Toxiques, UMR-I 01 INERIS, Amiens, France
- PhyToxE, Environmental Physio-Toxicity group, Rammal Hassan Rammal laboratory, Lebanese University, Faculty of Sciences, Nabatieh, Lebanon
| | - Hassan Khachfe
- Lebanese Institute for Biomedical Research and Application (LIBRA), Lebanese International University (LIU), Beirut, Lebanon
| | - Wissam Joumaa
- PhyToxE, Environmental Physio-Toxicity group, Rammal Hassan Rammal laboratory, Lebanese University, Faculty of Sciences, Nabatieh, Lebanon
| | - Véronique Bach
- PériTox, Périnatalité & Risques Toxiques, UMR-I 01 INERIS, Amiens, France
| | - Wiam Ramadan
- PhyToxE, Environmental Physio-Toxicity group, Rammal Hassan Rammal laboratory, Lebanese University, Faculty of Sciences, Nabatieh, Lebanon
- Lebanese Institute for Biomedical Research and Application (LIBRA), Lebanese International University (LIU), Beirut, Lebanon
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Wicher SA, Lawson KL, Jacoby DB, Fryer AD, Drake MG. Ozone-induced eosinophil recruitment to airways is altered by antigen sensitization and tumor necrosis factor- α blockade. Physiol Rep 2017; 5:e13538. [PMID: 29242307 PMCID: PMC5742702 DOI: 10.14814/phy2.13538] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 10/23/2017] [Accepted: 10/23/2017] [Indexed: 01/21/2023] Open
Abstract
Ozone is an atmospheric pollutant that causes lung inflammation and airway hyperresponsiveness. Ozone's effects occur in two distinct phases that are mediated by different populations of eosinophils. In the acute phase 1 day after exposure, mature airway-resident eosinophils alter parasympathetic nerve function that results in airway hyperresponsiveness. At this time point, the severity of hyperresponsiveness correlates with the number of eosinophils in close proximity to airway nerves, but not with eosinophils in bronchoalveolar lavage. Three days later, newly divided eosinophils are recruited to airways by a tumor necrosis factor-α-dependent mechanism. These new eosinophils paradoxically attenuate ozone-induced airway hyperresponsiveness. Ozone's effects on airway tissue eosinophils and nerve-associated eosinophils 3 days after exposure are unknown. Thus, we tested ozone's effects on eosinophils in airway subepithelium and around airway nerves 1 and 3 days after ozone in nonsensitized and ovalbumin-sensitized guinea pigs with or without the tumor necrosis factor-α antagonist, etanercept, and compared changes in eosinophils with ozone-induced airway hyperresponsiveness. More eosinophils were present in small, noncartilaginous airways and along small airway nerves compared to large cartilaginous airways in all treatment groups. The number of airway and nerve-associated eosinophils were unaffected 1 day after ozone exposure, whereas significantly fewer airway eosinophils were present 3 days later. Airway and nerve-associated eosinophils were also decreased in small airways 3 days after ozone in sensitized animals. These changes were blocked by etanercept. Airway eosinophils, but not nerve-associated or bronchoalveolar lavage eosinophils correlated with airway hyperresponsiveness 3 days after ozone. Our findings indicate ozone causes persistent alterations in airway eosinophils and reinforce the importance of characterizing eosinophils' effects within distinct airway compartments.
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Affiliation(s)
- Sarah A Wicher
- Department of Physiology and Pharmacology, Oregon Health & Sciences University, Portland, Oregon
| | - Katy L Lawson
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health & Science University, Portland, Oregon
| | - David B Jacoby
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health & Science University, Portland, Oregon
| | - Allison D Fryer
- Department of Physiology and Pharmacology, Oregon Health & Sciences University, Portland, Oregon
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health & Science University, Portland, Oregon
| | - Matthew G Drake
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health & Science University, Portland, Oregon
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Early changes in M2 muscarinic acetylcholine receptors (mAChRs) induced by sarin intoxication may be linked to long lasting neurological effects. Neurotoxicology 2017; 65:248-254. [PMID: 29128314 DOI: 10.1016/j.neuro.2017.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 11/05/2017] [Accepted: 11/05/2017] [Indexed: 01/08/2023]
Abstract
The effect of sarin on the binding parameters (KD & Bmax) of M2 muscarinic acetylcholine receptor (mAChR) was studied 24h and 1 week post exposure. Male & female Sprague-Daweley rats were poisoned with 1XLD50 sarin (80μg/kg, im) followed by treatment of trimedoxime bromide and atropine (7.5:5mg/kg, im) 1min later. Brains were removed and analyzed for M2 mAChR binding, using [3H]AFDX384, an M2 selective antagonist. A significant increase in KD of M2 mAChR was found in the cortex 24h post poisoning, displaying elevation from 4.65±1.16 to 8.45±1.06nM and 5.24±0.93 to 9.29±1.56nM in male and female rats, respectively. A rise in KD was also noted 1 week following exposure from 5.04±1.20 to 11.75±2.78 and from 5.37±1.02 to 11.66±1.73nM, presenting an added increase of 51 and 40% (compared to 24h) in males and females, respectively. Analysis of M2 receptor density (Bmax) revealed a significant reduction of 68% in males and insignificant reduction of 22% in females, 24h after sarin exposure which was followed by 37% recovery in males and 100% recovery in females, 1 week later. These results indicate that sarin induces a long-term decreased affinity in M2 mAChR (elevated KDs) and a transient effect on the number of this receptor subtype (Bmax). We hypothesize that the reduced affinity of the M2 receptors (negative auto-regulatory receptors) may cause long-term brain deficits by impairing the normal regulation release of ACh into the synaptic cleft.
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Kazemi M, Torbaghan AE, Tahmasbi AM, Valizadeh R, Naserian AA. Effects of phosalone consumption via feeding with or without sodium bentonite on performance, blood metabolites and its transition to milk of Iranian Baluchi sheep. JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2017; 59:10. [PMID: 28515956 PMCID: PMC5430607 DOI: 10.1186/s40781-017-0135-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 04/21/2017] [Indexed: 11/27/2022]
Abstract
BACKGROUND Transfer of pesticides from environment to animal products is inevitable, so the purpose of the present work was to evaluate phosalone consumption via feeding with or without sodium bentonite (SB) on performance, blood metabolites and its transition to milk of Iranian Baluchi sheep. METHODS Twenty Baluchi ewes were divided into four treatments (P1 as control, P2, P3, and P4) of five animals in which phosalone, an organophosphate pesticide, was given via diet (only for P2 and P3) at a dose of 280 mg/sheep/day for 63 consecutive days. The SB (32 g/sheep/day; for P3 and P4) was also evaluated for its ability to reduce deleterious effects of phosalone in the sheep diets. The control group (P1) did not receive any phosalone and SB during the experiment. Sampling was conducted in two periods of time including weeks 5 and 9. RESULTS Phosalone residues were observed in the milk samples of P2 and P3 groups during two sampling periods. During period 1, the transfer rate of phosalone from feed to milk was 0.23 and 0.02%, respectively for the contaminated diets (P2 and P3), which is relatively similar to period 2 (0.22 and 0.02%). Only 0.34 (period 1) and 0.36% (period 2) of phosalone residue are excreted in the feces of P2 group following its daily consumption. Transfer of phosalone from feed to milk was affected (P < 0.05) by the dietary inclusion of a commercial SB, as it (SB) decreased excretion of phosalone via milk (P3). The phosalone and SB alone or together had no significant effect (P > 0.05) on the dry matter intake (DMI) and body weight (BW) gain, but feed efficiency, milk production, milk fat, dry matter (DM) and organic matter (OM) digestibility, acetylcholinesterase (AChE) inhibitory activity, hemoglobin (Hb), red blood cell (RBC), serum glutamic pyruvic transaminase (SGPT), serum glutamic oxaloacetic transaminase (SGOT), albumin and mean corpuscular hemoglobin concentration (MCHC) affected by the treatments in period 1 or 2 (P < 0.05). The Hb, RBC, and MCHC were significantly decreased (P < 0.05) by about 9.72, 20.77, and 9.71%, respectively in the group P2 as compared to those of the control group during period 1. The AChE inhibitory activity (period 1 and 2) significantly increased when phosalone administered via the diet (P < 0.05). CONCLUSIONS Although there were no adverse effects on the performance of sheep following the intake of phosalone alone (P2 vs. P1), but other research on the long and short times to the phosalone in high and low doses with more animals is suggested. Overall, compared to the control group, addition of SB in the diet of sheep improved nutrient digestibility, animal performance, and milk health.
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Affiliation(s)
- Mohsen Kazemi
- Department of Animal Science, Faculty of Agriculture and Animal Science, University of Torbat-e Jam, Torbat-e Jam, Iran
| | - Ameneh Eskandary Torbaghan
- Department of Environmental Health Engineering, Torbat-e Jam Faculty of Medical Sciences, Torbat-e Jam, Iran
| | - Abdoul Mansour Tahmasbi
- Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Reza Valizadeh
- Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Abbas Ali Naserian
- Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
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Trailović SM, Marjanović DS, Uzelac TV, Milovanović M, Trailović JN. Two opposite dose-dependent effects of diazinon on the motor activity of the rat ileum. Res Vet Sci 2017; 112:18-25. [PMID: 28107667 DOI: 10.1016/j.rvsc.2017.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 12/05/2016] [Accepted: 01/05/2017] [Indexed: 11/25/2022]
Abstract
Acute poisoning with OPs may lead to a range of neurological effects, which cannot be explained by AChE inhibition alone. Several OPs interact directly with cholinergic receptors in mammals, but such data does not exist for invertebrates. The aim of current study was to investigate the direct and indirect effects of diazinon on the contractions of rat ileum and to compare those effects on the nervemuscle preparation of the Ascaris suum. In the presence of increasing concentrations of diazinon (3, 10 and 30nM), EFS-induced ileal contractions were increased significantly. In the same preparation, diazinon 3nM, significantly increased contractions induced by EFS, but did not affect the contractions caused by 5MFI. Contrarily, 1μM of diazinon significantly and reversibly inhibited the EFS-induced ileal contractions. Diazinon exhibited competitive and non-competitive inhibitions of 5MFI induced contractions. The control EC50 of 5MFI was 2.48μM with Rmax=1.88g. In the presence of diazinon, EC50 was 12.45μM, while Rmax was reduced to 0.43g. After washing, the EC50 and Rmax values were again closer to the control level (3.80μM and 1.04g). Diazinon 1μM did not inhibit Ascaris suum contractions caused by ACh, but it increased the Rmax. Diazinon in our study exhibits two opposite effects on the motor activity of the ileum. In low nanomolar concentrations the dominat is its effect on AChE and the stimulation of contractions. Furthermore, in concentrations that approach micromolar values diazinon has a direct inhibitory effect on muscarinic receptors. The direct inhibitory effect of diazinon on A. suum contractions was not found.
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Affiliation(s)
- Saša M Trailović
- Faculty of Veterinary Medicine, Department of Pharmacology and Toxicology, University of Belgrade, Bulevar oslobođenja 18, 11000 Beograd, Serbia.
| | - Djordje S Marjanović
- Faculty of Veterinary Medicine, Department of Pharmacology and Toxicology, University of Belgrade, Bulevar oslobođenja 18, 11000 Beograd, Serbia
| | - Teodora Vidonja Uzelac
- Institute for Biological Research "Siniša Stanković", Department of Physiology, University of Belgrade, Bulevar despota Stefana 142, 11060 Beograd, Serbia
| | - Mirjana Milovanović
- Faculty of Veterinary Medicine, Department of Pharmacology and Toxicology, University of Belgrade, Bulevar oslobođenja 18, 11000 Beograd, Serbia
| | - Jelena Nedeljković Trailović
- Faculty of Veterinary Medicine, Department of Nutrition, University of Belgrade, Bulevar oslobođenja 18, 11000 Beograd, Serbia
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Flunker LK, Nutter TJ, Johnson RD, Cooper BY. DEET potentiates the development and persistence of anticholinesterase dependent chronic pain signs in a rat model of Gulf War Illness pain. Toxicol Appl Pharmacol 2016; 316:48-62. [PMID: 28025109 DOI: 10.1016/j.taap.2016.12.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 12/16/2016] [Accepted: 12/20/2016] [Indexed: 12/18/2022]
Abstract
Exposure to DEET (N,N-diethyl-meta-toluamide) may have influenced the pattern of symptoms observed in soldiers with GWI (Gulf War Illness; Haley and Kurt, 1997). We examined how the addition of DEET (400mg/kg; 50% topical) to an exposure protocol of permethrin (2.6mg/kg; topical), chlorpyrifos (CP; 120mg/kg), and pyridostigmine bromide (PB;13mg/kg) altered the emergence and pattern of pain signs in an animal model of GWI pain (Nutter et al., 2015). Rats underwent behavioral testing before, during and after a 4week exposure: 1) hindlimb pressure withdrawal threshold; 2) ambulation (movement distance and rate); and 3) resting duration. Additional studies were conducted to assess the influence of acute DEET (10-100μM) on muscle and vascular nociceptor Kv7, KDR, Nav1.8 and Nav1.9. We report that a 50% concentration of DEET enhanced the development and persistence of pain-signs. Rats exposed to all 4 compounds exhibited ambulation deficits that appeared 5-12weeks post-exposure and persisted through weeks 21-24. Rats exposed to only three agents (CP or PB excluded), did not fully develop ambulation deficits. When PB was excluded, rats also developed rest duration pain signs, in addition to ambulation deficits. There was no evidence that physiological doses of DEET acutely modified nociceptor Kv7, KDR, Nav1.8 or Nav1.9 activities. Nevertheless, DEET augmented protocols decreased the conductance of Kv7 expressed in vascular nociceptors harvested from chronically exposed rats. We concluded that DEET enhanced the development and persistence of pain behaviors, but the anticholinesterases CP and PB played a determinant role.
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Affiliation(s)
- L K Flunker
- Division of Neuroscience, Dept. of Oral and Maxillofacial Surgery, Box 100416, JHMHC, University of Florida College of Dentistry, Gainesville, FL 32610, USA.
| | - T J Nutter
- Division of Neuroscience, Dept. of Oral and Maxillofacial Surgery, Box 100416, JHMHC, University of Florida College of Dentistry, Gainesville, FL 32610, USA.
| | - R D Johnson
- Dept. of Physiological Sciences, University of Florida College of Veterinary Science, Gainesville, FL 32610, USA.
| | - B Y Cooper
- Division of Neuroscience, Dept. of Oral and Maxillofacial Surgery, Box 100416, JHMHC, University of Florida College of Dentistry, Gainesville, FL 32610, USA.
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Mamane A, Raherison C, Tessier JF, Baldi I, Bouvier G. Environmental exposure to pesticides and respiratory health. Eur Respir Rev 2016; 24:462-73. [PMID: 26324808 DOI: 10.1183/16000617.00006114] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Respiratory effects of environmental exposure to pesticides are debated. Here we aimed to review epidemiological studies published up until 2013, using the PubMed database. 20 studies dealing with respiratory health and non-occupational pesticide exposure were identified, 14 carried out on children and six on adults. In four out of nine studies in children with biological measurements, mothers' dichlorodiphenyldichloroethylene (DDE) blood levels during pregnancy were associated with asthma and wheezing in young children. An association was also found between permethrin in indoor air during pregnancy and wheezing in children. A significant association between asthma and DDE measured in children's blood (aged 7-10 years) was observed in one study. However, in three studies, no association was found between asthma or respiratory infections in children and pesticide levels in breast milk and/or infant blood. Lastly, in three out of four studies where post-natal pesticide exposure of children was assessed by parental questionnaire an association with respiratory symptoms was found. Results of the fewer studies on pesticide environmental exposure and respiratory health of adults were much less conclusive: indeed, the associations observed were weak and often not significant. In conclusion, further studies are needed to confirm whether there is a respiratory risk associated with environmental exposure to pesticides.
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Affiliation(s)
- Ali Mamane
- ISPED - Laboratoire Santé Travail Environnement, Université de Bordeaux, Bordeaux, France ISPED - Centre INSERM U897-Epidémiologie-Biostatistique, Bordeaux, France
| | - Chantal Raherison
- ISPED - Laboratoire Santé Travail Environnement, Université de Bordeaux, Bordeaux, France ISPED - Centre INSERM U897-Epidémiologie-Biostatistique, Bordeaux, France Service des Maladies Respiratoire, CHU de Bordeaux, Bordeaux, France
| | | | - Isabelle Baldi
- ISPED - Laboratoire Santé Travail Environnement, Université de Bordeaux, Bordeaux, France ISPED - Centre INSERM U897-Epidémiologie-Biostatistique, Bordeaux, France Service de Médecine du Travail, CHU de Bordeaux, Bordeaux, France
| | - Ghislaine Bouvier
- ISPED - Laboratoire Santé Travail Environnement, Université de Bordeaux, Bordeaux, France ISPED - Centre INSERM U897-Epidémiologie-Biostatistique, Bordeaux, France
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Ghasemi-Niri SF, Maqbool F, Baeeri M, Gholami M, Abdollahi M. Phosalone-induced inflammation and oxidative stress in the colon: Evaluation and treatment. World J Gastroenterol 2016; 22:4999-5011. [PMID: 27275092 PMCID: PMC4886375 DOI: 10.3748/wjg.v22.i21.4999] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 04/08/2016] [Accepted: 05/04/2016] [Indexed: 02/07/2023] Open
Abstract
AIM To investigate the side effects of phosalone on intestinal cells and to evaluate benefits of ellagic acid (EA) as a remedy. METHODS In order to conduct an in vivo study, a rat model was used. The rats were divided into ten groups based on the materials used in the experiment and their dosage. The first group was fed normally. The second group was administered EA through gavage. Next Four groups were given (1/3, 1/5, 1/10, 1/20) LD50 phosalone; an organophosphorus compound. The last four groups received (1/3, 1/5, 1/10, 1/20) LD50 phosalone and of EA. After one month, the rats were sacrificed and their colon cells were examined to evaluate the level of inflammation, proteins and oxidative stress markers. RESULTS The results of this research show that phosalone elevates oxidative stress and changes the level of tumor necrosis factor-a (TNF-α), interlukin-6β (IL-6β) and nuclear factor (NF)-κB proteins. EA administration reduced phosalone toxicity and changed oxidative stress and inflammatory markers for all phosalone doses. Overall changes in reduction of TNF-α (230.47 ± 16.55 pg/mg protein vs 546.43 ± 45.24 pg/mg protein, P < 0.001), IL-6β (15.85 ± 1.03 pg/mg protein vs 21.55 ± 1.3 pg/mg protein, P < 0.05), and NF-κB (32.47 ± 4.85 pg/mg protein vs 51.41 ± 0.71 pg/mg protein, P < 0.05) manifest that the efficacy of EA is more viable for 1/3 LD50 dose of phosalone. Furthermore, EA is effective to counteract the negative outcomes of oxidative stress. When EA was used to treat 1/3 LD50 of phosalone's side effects, it improved the level of AChE activity (48.5% ± 6% vs 25% ± 7%, P < 0.05), TTM (0.391 ± 0.008 mmol/L vs 0.249 ± 0.032 mmol/L, P < 0.05), FRAP (46.04 ± 5.005 μmol/L vs 18.22 ± 1.9 μmol/L, P < 0.01) and MPO (0.222 ± 0.019 U/mg protein vs 0.387 ± 0.04 U/mg protein, P < 0.05). CONCLUSION This research highlights that EA is effective to alleviate the side effects of phosalone by reducing the level of oxidative stress and inflammatory proteins.
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Guler M, Turkoglu V, Kivrak A. Electrochemical detection of malathion pesticide using acetylcholinesterase biosensor based on glassy carbon electrode modified with conducting polymer film. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:12343-12351. [PMID: 26979315 DOI: 10.1007/s11356-016-6385-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 02/29/2016] [Indexed: 06/05/2023]
Abstract
Acetylcholinesterase (AChE) biosensor based on conducting poly([2,2̍';5̍' 2″]-terthiophene-3̍-carbaldehyde) (PTT) modified glassy carbon electrode (GCE) was constructed. AChE was immobilized on PTT film surface through the covalent bond between aldehyde and amino groups. The properties of PTT modified GCE were studied using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The biosensor showed an oxidation peak at +0.83 V related to the oxidation of thiocholine, hydrolysis product of acetylthiocholine iodide (ATCI), catalyzed by AChE. The optimum current response of the biosensor was observed at pH 7.5-8.0, 40 °C and 120 U/cm(2) of AChE concentration. The biosensor showed a high sensitivity (183.19 μA/mM), a linear range from 0.015 to 1.644 mM, and a good reproducibility with 1.7 % of relative standard deviation (RSD). The biosensor showed a good stability. The interference of glycin, ascorbic acid, histidine, uric acid, dopamine, and arginine on the biosensor response was studied. An important analytical response from these inteferents that overlaps the biosensor response was not observed. The inhibition rate of malathion as a model pesticide was proportional to its concentrations from 9.99 to 99.01 nM. The detection limit was 4.08 nM.
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Affiliation(s)
- Muhammet Guler
- Faculty of Science, Department of Chemistry, Yuzuncu Yil University, 65080, Van, Turkey.
| | - Vedat Turkoglu
- Faculty of Science, Department of Chemistry, Yuzuncu Yil University, 65080, Van, Turkey
| | - Arif Kivrak
- Faculty of Science, Department of Chemistry, Yuzuncu Yil University, 65080, Van, Turkey
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Cooper BY, Johnson RD, Nutter TJ. Exposure to Gulf War Illness chemicals induces functional muscarinic receptor maladaptations in muscle nociceptors. Neurotoxicology 2016; 54:99-110. [PMID: 27058124 DOI: 10.1016/j.neuro.2016.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 03/31/2016] [Accepted: 04/01/2016] [Indexed: 12/12/2022]
Abstract
Chronic pain is a component of the multisymptom disease known as Gulf War Illness (GWI). There is evidence that pain symptoms could have been a consequence of prolonged and/or excessive exposure to anticholinesterases and other GW chemicals. We previously reported that rats exposed, for 8 weeks, to a mixture of anticholinesterases (pyridostigmine bromide, chlorpyrifos) and a Nav (voltage activated Na(+) channel) deactivation-inhibiting pyrethroid, permethrin, exhibited a behavior pattern that was consistent with a delayed myalgia. This myalgia-like behavior was accompanied by persistent changes to Kv (voltage activated K(+)) channel physiology in muscle nociceptors (Kv7, KDR). In the present study, we examined how exposure to the above agents altered the reactivity of Kv channels to a muscarinic receptor (mAChR) agonist (oxotremorine-M). Comparisons between muscle nociceptors harvested from vehicle and GW chemical-exposed rats revealed that mAChR suppression of Kv7 activity was enhanced in exposed rats. Yet in these same muscle nociceptors, a Stromatoxin-insensitive component of the KDR (voltage activated delayed rectifier K(+) channel) exhibited decreased sensitivity to activation of mAChR. We have previously shown that a unique mAChR-induced depolarization and burst discharge (MDBD) was exaggerated in muscle nociceptors of rats exposed to GW chemicals. We now provide evidence that both muscle and vascular nociceptors of naïve rats exhibit MDBD. Examination of the molecular basis of the MDBD in naïve animals revealed that while the mAChR depolarization was independent of Kv7, the action potential burst was modulated by Kv7 status. mAChR depolarizations were shown to be dependent, in part, on TRPA1. We argue that dysfunction of the MDBD could be a functional convergence point for maladapted ion channels and receptors consequent to exposure to GW chemicals.
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Affiliation(s)
- B Y Cooper
- Division of Neuroscience, Dept. of Oral and Maxillofacial Surgery, Box 100416, JHMHC, University of Florida College of Dentistry, Gainesville, FL 32610, USA.
| | - R D Johnson
- Dept. of Physiological Sciences, University of Florida College of Veterinary Science, Gainesville, FL 32610, USA.
| | - T J Nutter
- Division of Neuroscience, Dept. of Oral and Maxillofacial Surgery, Box 100416, JHMHC, University of Florida College of Dentistry, Gainesville, FL 32610, USA.
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Ye M, Beach J, Martin JW, Senthilselvan A. Urinary Dialkyl Phosphate Concentrations and Lung Function Parameters in Adolescents and Adults: Results from the Canadian Health Measures Survey. ENVIRONMENTAL HEALTH PERSPECTIVES 2016; 124:491-7. [PMID: 26372667 PMCID: PMC4829996 DOI: 10.1289/ehp.1509745] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 09/11/2015] [Indexed: 05/14/2023]
Abstract
BACKGROUND Epidemiological studies have reported associations between lung function parameters and organophosphate (OP) pesticide exposures in agricultural occupations, but to our knowledge associations have not been evaluated in general populations. OBJECTIVES We examined associations between OP metabolite dialkyl phosphates (DAPs) and lung function using data from the Canadian Health Measures Survey (CHMS) Cycle 1. METHODS Forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), FEV1/FVC ratio, and forced expiratory flow between 25% and 75% of FVC (FEF25%-75%) were measured for 4,446 CHMS participants. Urinary concentrations of six DAP metabolites (DMP, DMTP, DMDTP, DEP, DETP, and DEDTP), smoking status, and other predictors of lung function were also measured in the CHMS-Cycle 1. Multiple linear regression analyses were used to examine the relationship between total DAP concentrations (ΣDAPs) and lung function in adolescents (12-19 years) and adults (20-79 years). RESULTS In adults, estimates from multiple regression analyses suggested that a 1-unit increase on natural logarithmic scale (171% increase on the original scale) in the creatinine-corrected urinary concentration (nanomoles per gram creatinine) of ΣDAP was associated with a 32.6-mL (95% CI: -57.2, -8.1) reduction in FVC, 32.6-mL (95% CI: -59.0, -6.3) reduction in FEV1, 0.2% (95% CI: -0.6, 0.2) reduction in FEV1/FVC ratio, and 53.1-mL/sec (95% CI: -113.9, 7.7) reduction in FEF25%-75%. In adolescents, associations between ΣDAP and FEV1 were closer to the null and positive for FVC, whereas associations with FEV1/FVC and FEF25%-75% were negative, as in adults. However, none of the associations were significant in adolescents. CONCLUSIONS The negative association between ΣDAP and lung function in adult participants suggests a detrimental effect of OP pesticides on lung function in the adult general population. Further studies using prospective designs are warranted to confirm the findings reported in this study. CITATION Ye M, Beach J, Martin JW, Senthilselvan A. 2016. Urinary dialkyl phosphate concentrations and lung function parameters in adolescents and adults: results from the Canadian Health Measures Survey. Environ Health Perspect 124:491-497; http://dx.doi.org/10.1289/ehp.1509745.
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Affiliation(s)
- Ming Ye
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
| | - Jeremy Beach
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
- Division of Preventive Medicine, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Jonathan W. Martin
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Ambikaipakan Senthilselvan
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
- Address correspondence to A. Senthilselvan, School of Public Health, University of Alberta, 3-276 Edmonton Heath Clinic Academy, 11405–87 Ave., Edmonton, Alberta, T6G 1C9 Canada. Telephone: (780) 492 6505. E-mail:
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Chlorpyrifos exposure and respiratory health among adolescent agricultural workers. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2014; 11:13117-29. [PMID: 25522051 PMCID: PMC4276666 DOI: 10.3390/ijerph111213117] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 12/04/2014] [Accepted: 12/11/2014] [Indexed: 11/29/2022]
Abstract
Chlorpyrifos (CPF) is a commonly used organophosphate insecticide (OP). In adults, exposure to OPs has been inconsistently associated with reduced lung function. OP exposure and lung function has not been assessed in adolescents. The objective of this study was to assess CPF exposure and lung function among Egyptian adolescents. We conducted a 10-month study of male adolescent pesticide applicators (n = 38) and non-applicators of similar age (n = 24). Urinary 3,5,6-trichloro-2-pyridinol (TPCy), a CPF-specific metabolite, was analyzed in specimens collected throughout the study. Spirometry was performed twice after pesticide application: day 146, when TCPy levels were elevated and day 269, when TCPy levels were near baseline. Applicators had higher levels of TCPy (mean cumulative TCPy day 146 = 33,217.6; standard deviation (SD) = 49,179.3) than non-applicators (mean cumulative TCPy day 146 = 3290.8; SD = 3994.9). Compared with non-applicators, applicators had higher odds of reporting wheeze, odds ratio = 3.41 (95% CI: 0.70; 17.41). Cumulative urinary TCPy was inversely associated with spirometric measurements at day 146, but not at day 269. Although generally non-significant, results were consistent with an inverse association between exposure to CPF and lung function.
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Prins JM, Chao CK, Jacobson SM, Thompson CM, George KM. Oxidative stress resulting from exposure of a human salivary gland cells to paraoxon: an in vitro model for organophosphate oral exposure. Toxicol In Vitro 2014; 28:715-21. [PMID: 24486155 DOI: 10.1016/j.tiv.2014.01.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 01/17/2014] [Accepted: 01/20/2014] [Indexed: 11/19/2022]
Abstract
Organophosphate (OP) compounds are used as insecticides, acaricides, and chemical agents and share a common neurotoxic mechanism of action. The biochemical alterations leading to many of the deleterious effects have been studied in neuronal cell lines, however, non-neuronal toxic effects of OPs are far less well characterized in vitro, and specifically in cell lines representing oral routes of exposure. To address this void, the human salivary gland (HSG) cell line, representing likely interactions in the oral cavity, was exposed to the representative OP paraoxon (PX; O,O-diethyl-p-nitrophenoxy phosphate) over a range of concentrations (0.01-100 μM) and analyzed for cytotoxicity. PX induced cytotoxicity in HSG cells at most of the exposure concentrations as revealed by MTT assay, however, the release of LDH only occurred at the highest concentration of PX tested (100 μM) at 48 h. Slight increases in cellular ATP levels were measured in PX-exposed (10 μM) HSG cells at 24 h. Exposing HSG cells to 10 μM PX also led to an increase in DNA fragmentation prior to loss of cellular membrane integrity implicating reactive oxygen species (ROS) as a trigger of toxicity. The ROS genes gss, gstm2, gstt2 and sod2 were upregulated, and the presence of superoxide following 10 μM PX exposure was determined via dihydroethidium fluorescence studies further implicating PX-induced oxidative stress in HSG cells.
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Affiliation(s)
- John M Prins
- Department of Biomedical and Pharmaceutical Sciences, College of Health Professions and Biomedical Sciences, The University of Montana, Missoula, MT 59812, United States
| | - Chih-Kai Chao
- Department of Biomedical and Pharmaceutical Sciences, College of Health Professions and Biomedical Sciences, The University of Montana, Missoula, MT 59812, United States
| | - Saskia M Jacobson
- Department of Biomedical and Pharmaceutical Sciences, College of Health Professions and Biomedical Sciences, The University of Montana, Missoula, MT 59812, United States
| | - Charles M Thompson
- Department of Biomedical and Pharmaceutical Sciences, College of Health Professions and Biomedical Sciences, The University of Montana, Missoula, MT 59812, United States.
| | - Kathleen M George
- Department of Biomedical and Pharmaceutical Sciences, College of Health Professions and Biomedical Sciences, The University of Montana, Missoula, MT 59812, United States.
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Killi UK, Wsol V, Soukup O, Kuca K, Winder M, Tobin G. In vitro functional interactions of acetylcholine esterase inhibitors and muscarinic receptor antagonists in the urinary bladder of the rat. Clin Exp Pharmacol Physiol 2013; 41:139-46. [PMID: 24341923 DOI: 10.1111/1440-1681.12191] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 11/05/2013] [Accepted: 11/07/2013] [Indexed: 11/27/2022]
Abstract
Obidoxime, a weak acetylcholine-esterase (AChE) inhibitor, exerts muscarinic receptor antagonism with a significant muscarinic M2 receptor selective profile. The current examinations aimed to determine the functional significance of muscarinic M2 receptors in the state of AChE inhibition, elucidating muscarinic M2 and M3 receptor interaction. In the in vitro examinations, methacholine evoked concentration-dependent bladder contractile and atrial frequency inhibitory responses. Although atropine abolished both, methoctramine (1 μmol/L) only affected the cholinergic response in the atrial preparations. However, in the presence of methoctramine, physostigmine, an AChE inhibitor, increased the basal tension of the bladder strip preparations (+68%), as well as the contractile responses to low concentrations of methacholine (< 5 μmol/L; +90-290%). In contrast to physostigmine, obidoxime alone raised the basal tension (+58%) and the responses to low concentrations of methacholine (< 5 μmol/L; +80-450%). Physostigmine concentration-dependently increased methacholine-evoked responses, similarly to obidoxime at low concentrations. However, at large concentrations (> 5 μmol/L), obidoxime, because of its unselective muscarinic receptor antagonism, inhibited the methacholine bladder responses. In conclusion, the current results show that muscarinic M2 receptors inhibit muscarinic M3 receptor-evoked contractile responses to low concentrations of acetylcholine in the synaptic cleft. The muscarinic M2 and M3 receptor crosstalk could be a counteracting mechanism in the treatment of AChE inhibition when using reactivators, such as obidoxime.
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Affiliation(s)
- Uday K Killi
- Department of Biochemical Sciences, Faculty of Pharmacy, Charles University, Hradec Kralove, Czech Republic
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Watanabe Y, Itoh T, Shiraishi H, Maeno Y, Arima Y, Torikoshi A, Namera A, Makita R, Yoshizumi M, Nagao M. Acute effects of a sarin-like organophosphorus agent, bis(isopropyl methyl)phosphonate, on cardiovascular parameters in anaesthetized, artificially ventilated rats. Toxicol Appl Pharmacol 2013; 272:61-6. [DOI: 10.1016/j.taap.2013.06.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 05/29/2013] [Accepted: 06/05/2013] [Indexed: 11/30/2022]
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Proskocil BJ, Bruun DA, Jacoby DB, van Rooijen N, Lein PJ, Fryer AD. Macrophage TNF-α mediates parathion-induced airway hyperreactivity in guinea pigs. Am J Physiol Lung Cell Mol Physiol 2013; 304:L519-29. [PMID: 23377347 DOI: 10.1152/ajplung.00381.2012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Organophosphorus pesticides (OPs) are implicated in human asthma. We previously demonstrated that, at concentrations that do not inhibit acetylcholinesterase activity, the OP parathion causes airway hyperreactivity in guinea pigs as a result of functional loss of inhibitory M2 muscarinic receptors on parasympathetic nerves. Because macrophages are associated with asthma, we investigated whether macrophages mediate parathion-induced M2 receptor dysfunction and airway hyperreactivity. Airway physiology was measured in guinea pigs 24 h after a subcutaneous injection of parathion. Pretreatment with liposome-encapsulated clodronate induced alveolar macrophage apoptosis and prevented parathion-induced airway hyperreactivity in response to electrical stimulation of the vagus nerves. As determined by qPCR, TNF-α and IL-1β mRNA levels were increased in alveolar macrophages isolated from parathion-treated guinea pigs. Parathion treatment of alveolar macrophages ex vivo did not significantly increase IL-1β and TNF-α mRNA but did significantly increase TNF-α protein release. Consistent with these data, pretreatment with the TNF-α inhibitor etanercept but not the IL-1β receptor inhibitor anakinra prevented parathion-induced airway hyperreactivity and protected M2 receptor function. These data suggest a novel mechanism of OP-induced airway hyperreactivity in which low-level parathion activates macrophages to release TNF-α-causing M2 receptor dysfunction and airway hyperreactivity. These observations have important implications regarding therapeutic approaches for treating respiratory disease associated with OP exposures.
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Affiliation(s)
- Becky J Proskocil
- Division of Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, OR 97239, USA.
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Terry AV. Functional consequences of repeated organophosphate exposure: potential non-cholinergic mechanisms. Pharmacol Ther 2012; 134:355-65. [PMID: 22465060 DOI: 10.1016/j.pharmthera.2012.03.001] [Citation(s) in RCA: 159] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 03/01/2012] [Indexed: 12/29/2022]
Abstract
The class of chemicals known as the "organophosphates" (OPs) comprises many of the most common agricultural and commercial pesticides that are used worldwide as well as the highly toxic chemical warfare agents. The mechanism of the acute toxicity of OPs in both target and non-target organisms is primarily attributed to inhibitory actions on various forms of cholinesterase leading to excessive peripheral and central cholinergic activity. However, there is now substantial evidence that this canonical (cholinesterase-based) mechanism cannot alone account for the wide-variety of adverse consequences of OP exposure that have been described, especially those associated with repeated exposures to levels that produce no overt signs of acute toxicity. This type of exposure has been associated with prolonged impairments in attention, memory, and other domains of cognition, as well as chronic illnesses where these symptoms are manifested (e.g., Gulf War Illness, Alzheimer's disease). Due to their highly reactive nature, it is not surprising that OPs might alter the function of a number of enzymes and proteins (in addition to cholinesterase). However, the wide variety of long-term neuropsychiatric symptoms that have been associated with OPs suggests that some basic or fundamental neuronal process was adversely affected during the exposure period. The purpose of this review is to discuss several non-cholinesterase targets of OPs that might affect such fundamental processes and includes cytoskeletal and motor proteins involved in axonal transport, neurotrophins and their receptors, and mitochondria (especially their morphology and movement in axons). Potential therapeutic implications of these OP interactions are also discussed.
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Affiliation(s)
- A V Terry
- Department of Pharmacology and Toxicology, Georgia Health Sciences University, Augusta, GA 30912, USA.
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Abstract
PURPOSE OF REVIEW Several clinical and epidemiological studies have reported an association between exposure to pesticides, bronchial hyper-reactivity and asthma symptoms. This article reviews the mechanistic evidence lending support to the concept that either acute or chronic low-level inhalation of pesticides may trigger asthma attacks, exacerbate asthma or increase the risk of developing asthma. RECENT FINDINGS Pesticide aerosols or gases, like other respiratory irritants, can lead to asthma through interaction with functional irritant receptors in the airway and promoting neurogenic inflammation. Cross-talk between airway nerves and inflammatory cells helps to maintain chronic inflammation that eventually damages the bronchial epithelium. Certain organophosphorus insecticides cause airway hyper-reactivity via a common mechanism of disrupting negative feedback control of cholinergic regulation in the lungs. These pesticides may interact synergistically with allergen sensitization rendering individuals more susceptible for developing asthma. SUMMARY Many pesticides are sensitizers or irritants capable of directly damaging the bronchial mucosa, thus making the airway very sensitive to allergens or other stimuli. However, most pesticides are weakly immunogenic so that their potential to sensitize airways in exposed populations is limited. Pesticides may increase the risk of developing asthma, exacerbate a previous asthmatic condition or even trigger asthma attacks by increasing bronchial hyper-responsiveness.
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Current world literature. Curr Opin Allergy Clin Immunol 2011; 11:150-6. [PMID: 21368622 DOI: 10.1097/aci.0b013e3283457ab0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Deterioration in brain and heart functions following a single sub-lethal (0.8 LCt50) inhalation exposure of rats to sarin vapor: a putative mechanism of the long term toxicity. Toxicol Appl Pharmacol 2011; 253:31-7. [PMID: 21419149 DOI: 10.1016/j.taap.2011.03.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2011] [Revised: 03/06/2011] [Accepted: 03/08/2011] [Indexed: 11/22/2022]
Abstract
The main injuries among victims of the terrorist act in the Tokyo subway resulted from sub-lethal inhalation and whole body exposure to sarin vapor. In order to study the long term effects of such exposure and to simulate these conditions, freely moving rats were exposed to sarin vapor (27.2±1.7 μg/l) for 10 min. About 50% of the rats showed no overt symptoms and the rest had mild to moderate clinical symptoms that subsided within 4h following exposure. A reduction of weight was noted during the first 3 days with full recovery on the 4th day. Rat's heart was challenged with epinephrine 1 and 6 months post exposure. A significant reduction in the threshold for epinephrine-induced arrhythmia (EPIA) was noted in rats exposed to sarin. A time dependent increase in the kD and Bmax values of muscarinic auto receptors (M2) was recorded in the rat's cortex and striatum. No changes were recorded in the rats' brain trans locator protein (TSPO) levels, concomitant with no observed changes in the animals' performance in A Morris water maze test. A significant increase in open field activity was noted 6 months following exposure to sarin vapor as well as a significant decrease in prostaglandin E₂ (PGE₂) production in the brain. It is speculated that down regulation of the M2 auto receptor function, caused hyper reactivity of the cholinergic system which leads to the changes described above. The continuous reduction in M2 auto-receptor system through an unknown mechanism may be the cause for long lasting decline in sarin-exposed casualties' health.
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