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Chern CR, Lauková M, Schonwald A, Kudová E, Chodounská H, Chern CJ, Shakarjian MP, Velíšková J, Velíšek L. Novel neurosteroid pregnanolone pyroglutamate suppresses neurotoxicity syndrome induced by tetramethylenedisulfotetramine but is ineffective in a rodent model of infantile spasms. Pharmacol Rep 2023; 75:177-188. [PMID: 36422805 PMCID: PMC10785007 DOI: 10.1007/s43440-022-00437-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 11/14/2022] [Accepted: 11/15/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND Neurosteroids are investigated as effective antidotes for the poisoning induced by tetramethylenedisulfotetramine (TMDT) as well as treatments for epileptic spasms during infancy. Both these conditions are quite resistant to pharmacotherapy; thus, a search for new treatments is warranted. METHODS In this study, we determined the efficacy of two novel neurosteroids, pregnanolone glutamate (PAG) and pregnanolone pyroglutamate (PPG), and tested these drugs in doses of 1-10 mg/kg (ip) against the TMDT syndrome and in our rodent model of infantile spasms. RESULTS Only PPG in doses 5 and 10 mg/kg suppressed the severity of the TMDT syndrome and TMDT-induced lethality, while the 1 mg/kg dose was without an effect. Interestingly, the 1 mg/kg dose of PPG in combination with 1 mg/kg of diazepam was also effective against TMDT poisoning. Neither PAG nor PPG were effective against experimental spasms in the N-methyl-D-aspartate (NMDA)-triggered model of infantile spasms. CONCLUSIONS While evidence suggests that PAG can act through multiple actions which include allosteric inhibition of NMDA-induced and glycine receptor-evoked currents as well as augmentation of ɣ-aminobutyric acid subtype A (GABAA) receptor-induced currents, the agent appears to neither have the appropriate mechanistic signature for activity in the infantile spasm model, nor the adequate potency, relative to PPG, for ameliorating the TMDT syndrome. The full mechanisms of action of PPG, which may become a potent TMDT antidote either alone or in combination with diazepam are yet unknown and thus require further investigation.
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Affiliation(s)
- Chian-Ru Chern
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
| | - Marcela Lauková
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
- Institute of Experimental Endocrinology, Biomedical Research Center of the Slovak Academy of Science, Bratislava, Slovakia
| | - Antonia Schonwald
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
| | - Eva Kudová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Hana Chodounská
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Chian-Jiang Chern
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
| | - Michael P Shakarjian
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
- Department of Public Health, Environmental Health Science Program, New York Medical College, Valhalla, NY, USA
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Rutgers-Robert Wood Johnson Medical School, 675 Hoes Ln W, Piscataway, NJ, 08854, USA
| | - Jana Velíšková
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
- Department of Obstetrics and Gynecology, New York Medical College, Valhalla, NY, USA
- Department of Neurology, New York Medical College, Valhalla, NY, USA
| | - Libor Velíšek
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA.
- Department of Neurology, New York Medical College, Valhalla, NY, USA.
- Department of Pediatrics, New York Medical College, Valhalla, NY, USA.
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Calsbeek JJ, González EA, Boosalis CA, Zolkowska D, Bruun DA, Rowland DJ, Saito NH, Harvey DJ, Chaudhari AJ, Rogawski MA, Garbow JR, Lein PJ. Strain differences in the extent of brain injury in mice after tetramethylenedisulfotetramine-induced status epilepticus. Neurotoxicology 2021; 87:43-50. [PMID: 34478772 PMCID: PMC8595842 DOI: 10.1016/j.neuro.2021.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/28/2021] [Accepted: 08/29/2021] [Indexed: 11/30/2022]
Abstract
Acute intoxication with tetramethylenedisulfotetramine (TETS) can trigger status epilepticus (SE) in humans. Survivors often exhibit long-term neurological effects, including electrographic abnormalities and cognitive deficits, but the pathogenic mechanisms linking the acute toxic effects of TETS to chronic outcomes are not known. Here, we use advanced in vivo imaging techniques to longitudinally monitor the neuropathological consequences of TETS-induced SE in two different mouse strains. Adult male NIH Swiss and C57BL/6J mice were injected with riluzole (10 mg/kg, i.p.), followed 10 min later by an acute dose of TETS (0.2 mg/kg in NIH Swiss; 0.3 mg/kg, i.p. in C57BL/6J) or an equal volume of vehicle (10% DMSO in 0.9% sterile saline). Different TETS doses were administered to trigger comparable seizure behavior between strains. Seizure behavior began within minutes of TETS exposure and rapidly progressed to SE that was terminated after 40 min by administration of midazolam (1.8 mg/kg, i.m.). The brains of vehicle and TETS-exposed mice were imaged using in vivo magnetic resonance (MR) and translocator protein (TSPO) positron emission tomography (PET) at 1, 3, 7, and 14 days post-exposure to monitor brain injury and neuroinflammation, respectively. When the brain scans of TETS mice were compared to those of vehicle controls, subtle and transient neuropathology was observed in both mouse strains, but more extensive and persistent TETS-induced neuropathology was observed in C57BL/6J mice. In addition, one NIH Swiss TETS mouse that did not respond to the midazolam therapy, but remained in SE for more than 2 h, displayed robust neuropathology as determined by in vivo imaging and confirmed by FluoroJade C staining and IBA-1 immunohistochemistry as readouts of neurodegeneration and neuroinflammation, respectively. These findings demonstrate that the extent of injury observed in the mouse brain after TETS-induced SE varied according to strain, dose of TETS and/or the duration of SE. These observations suggest that TETS-intoxicated humans who do not respond to antiseizure medication are at increased risk for brain injury.
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Affiliation(s)
- Jonas J Calsbeek
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA, 95616, USA.
| | - Eduardo A González
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA, 95616, USA.
| | - Casey A Boosalis
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA, 95616, USA.
| | - Dorota Zolkowska
- Department of Neurology, University of California, Davis, School of Medicine, Davis, CA, 95616, USA.
| | - Donald A Bruun
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA, 95616, USA.
| | - Douglas J Rowland
- Center for Molecular and Genomic Imaging, University of California, Davis, College of Engineering, Davis, CA, 95616, USA.
| | - Naomi H Saito
- Department of Public Health Sciences, University of California, Davis, School of Medicine, Davis, CA, 95616, USA.
| | - Danielle J Harvey
- Department of Public Health Sciences, University of California, Davis, School of Medicine, Davis, CA, 95616, USA.
| | - Abhijit J Chaudhari
- Center for Molecular and Genomic Imaging, University of California, Davis, College of Engineering, Davis, CA, 95616, USA.
| | - Michael A Rogawski
- Department of Neurology, University of California, Davis, School of Medicine, Davis, CA, 95616, USA.
| | - Joel R Garbow
- Biomedical Magnetic Resonance Laboratory, Mallinckrodt Institute of Radiology, Washington University in St. Louis, School of Medicine, St. Louis, MO, 63110, USA.
| | - Pamela J Lein
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA, 95616, USA.
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Zolkowska D, Dhir A, Rogawski MA. Perampanel, a potent AMPA receptor antagonist, protects against tetramethylenedisulfotetramine-induced seizures and lethality in mice: comparison with diazepam. Arch Toxicol 2021; 95:2459-2468. [PMID: 33914090 PMCID: PMC8241714 DOI: 10.1007/s00204-021-03053-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/15/2021] [Indexed: 11/08/2022]
Abstract
Tetramethylenedisulfotetramine (TETS), a noncompetitive GABAA receptor antagonist, is a potent, highly lethal convulsant that is considered to be a chemical threat agent. Here, we assessed the ability of the AMPA receptor antagonist perampanel to protect against TETS-induced seizures and lethality in mice when administered before or after treatment with the toxicant. For comparison, we conducted parallel testing with diazepam, which is a first-line treatment for chemically induced seizures in humans. Pre-treatment of mice with either perampanel (1–4 mg/kg, i.p.) or diazepam (1–5 mg/kg, i.p.) conferred protection in a dose-dependent fashion against tonic seizures and lethality following a dose of TETS (0.2 mg/kg, i.p.) that rapidly induces seizures and death. The ED50 values for protection against mortality were 1.6 mg/kg for perampanel and 2.1 mg/kg for diazepam. Clonic seizures were unaffected by perampanel and only prevented in a minority of animals by high-dose diazepam. Neither treatment prevented myoclonic body twitches. Perampanel and diazepam also conferred protection against tonic seizures and lethality when administered 15 min following a 0.14 mg/kg, i.p., dose of TETS and 5 min following a 0.2 mg/kg, i.p., dose of TETS. Both posttreatments were highly potent at reducing tonic seizures and lethality in animals exposed to the lower dose of TETS whereas greater doses of both treatments were required in animals exposed to the larger dose of TETS. Neither treatment was as effective suppressing clonic seizures. In an experiment where 0.4 mg/kg TETS was administered by oral gavage and the treatment drugs were administered 5 min later, perampanel only partially protected against lethality whereas diazepam produced nearly complete protection. We conclude that perampanel and diazepam protect against TETS-induced tonic seizures and lethality but have less impact on clonic seizures. Both drugs could have utility in the treatment of TETS intoxication but neither eliminates all seizure activity.
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Affiliation(s)
- Dorota Zolkowska
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA, 95817, USA
| | - Ashish Dhir
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA, 95817, USA
| | - Michael A Rogawski
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA, 95817, USA. .,Department of Pharmacology, School of Medicine, University of California, Davis, Sacramento, CA, 95817, USA.
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Comparison of the toxicokinetics of the convulsants picrotoxinin and tetramethylenedisulfotetramine (TETS) in mice. Arch Toxicol 2020; 94:1995-2007. [PMID: 32239239 PMCID: PMC7303059 DOI: 10.1007/s00204-020-02728-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 03/26/2020] [Indexed: 12/15/2022]
Abstract
Acute intoxication with picrotoxin or the rodenticide tetramethylenedisulfotetramine (TETS) can cause seizures that rapidly progress to status epilepticus and death. Both compounds inhibit γ-aminobutyric acid type-A (GABAA) receptors with similar potency. However, TETS is approximately 100 × more lethal than picrotoxin. Here, we directly compared the toxicokinetics of the two compounds following intraperitoneal administration in mice. Using LC/MS analysis we found that picrotoxinin, the active component of picrotoxin, hydrolyses quickly into picrotoxic acid, has a short in vivo half-life, and is moderately brain penetrant (brain/plasma ratio 0.3). TETS, in contrast, is not metabolized by liver microsomes and persists in the body following intoxication. Using both GC/MS and a TETS-selective immunoassay we found that mice administered TETS at the LD50 of 0.2 mg/kg in the presence of rescue medications exhibited serum levels that remained constant around 1.6 μM for 48 h before falling slowly over the next 10 days. TETS showed a similar persistence in tissues. Whole-cell patch-clamp demonstrated that brain and serum extracts prepared from mice at 2 and 14 days after TETS administration significantly blocked heterologously expressed α2β3γ2 GABAA-receptors confirming that TETS remains pharmacodynamically active in vivo. This observed persistence may contribute to the long-lasting and recurrent seizures observed following human exposures. We suggest that countermeasures to neutralize TETS or accelerate its elimination should be explored for this highly dangerous threat agent.
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Moffett MC, Rauscher NA, Rice NC, Myers TM. Survey of drug therapies against acute oral tetramethylenedisulfotetramine poisoning in a rat voluntary consumption model. Neurotoxicology 2019; 74:264-271. [DOI: 10.1016/j.neuro.2019.08.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 07/30/2019] [Accepted: 08/05/2019] [Indexed: 12/12/2022]
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Lauková M, Velíšková J, Velíšek L, Shakarjian MP. Tetramethylenedisulfotetramine neurotoxicity: What have we learned in the past 70 years? Neurobiol Dis 2019; 133:104491. [PMID: 31176716 DOI: 10.1016/j.nbd.2019.104491] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/27/2019] [Accepted: 06/05/2019] [Indexed: 12/21/2022] Open
Abstract
Tetramethylenedisulfotetramine (tetramine, TETS, TMDT) is a seizure-producing neurotoxic chemical formed by the condensation of sulfamide and formaldehyde. Serendipitously discovered through an occupational exposure in 1949, it was promoted as a rodenticide but later banned worldwide due to its danger to human health. However, exceptional activity of the agent against rodent pests resulted in its clandestine manufacture with large numbers of inadvertent, intentional, and mass poisonings, which continue to this day. Facile synthesis, extreme potency, persistence, lack of odor, color, and taste identify it as an effective food adulterant and potential chemical agent of terror. No known antidote or targeted treatment is currently available. In this review we examine the origins of tetramethylenedisulfotetramine, from its identification as a neurotoxicant 70 years ago, through early research, to the most recent findings including the risk it poses in the post-911 world. Included is the information known regarding its in vitro pharmacology as a GABAA receptor channel antagonist, the toxic syndrome it produces in vivo, and its effect upon vulnerable populations. We also summarize the available information about potential therapeutic countermeasures and treatment strategies as well as the contribution of clinical development of TMDT poisoning to our understanding of epileptogenesis. Finally we identify gaps in our knowledge and suggest potentially fruitful directions for continued research on this dangerous, yet intriguing compound.
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Affiliation(s)
- Marcela Lauková
- Department of Public Health, Division of Environmental Health Science, School of Health Sciences and Practice, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Department of Pediatrics, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 84505, Slovakia
| | - Jana Velíšková
- Department of Cell Biology and Anatomy, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Department of Obstetrics and Gynecology, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Department of Neurology, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA
| | - Libor Velíšek
- Department of Cell Biology and Anatomy, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Department of Neurology, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Department of Pediatrics, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA
| | - Michael P Shakarjian
- Department of Public Health, Division of Environmental Health Science, School of Health Sciences and Practice, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Department of Cell Biology and Anatomy, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Department of Medicine, Division of Pulmonary and Critical Care Medicine, Rutgers-Robert Wood Johnson Medical School, 675 Hoes Ln W, Piscataway, NJ 08854, USA.
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Mouse model of human poisonings with tetramethylenedisulfotetramine: Characterization of the effect of exposure route on syndrome outcomes. Toxicol Lett 2019; 308:50-55. [PMID: 30940550 DOI: 10.1016/j.toxlet.2019.03.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/22/2019] [Accepted: 03/29/2019] [Indexed: 12/18/2022]
Abstract
Tetramethylenedisulfotetramine (TMDT) is a synthetic neurotoxic rodenticide and potential chemical threat agent. Signs of TMDT poisoning include convulsions which can progress into status epilepticus and death. Although clinical reports clearly show that poisoning via food and drink is the main route of exposure, experimental studies have primarily utilized parenteral routes. Here we used two different modes of oral administration of TMDT and compared the toxic outcomes with two different parenteral routes. Adult male mice were given various doses of TMDT either perorally in peanut butter or cereal pellets, or injected intraperitoneally (i.p.) or subcutaneously (s.c.). All routes produced the complete TMDT syndrome including twitches, clonic and tonic-clonic seizures and death. However potencies varied with the following rank order: i.p. > s.c. > oral (cereal)>>oral (peanut butter). Our data clearly show that ingestion of TMDT with peanut butter markedly reduces the overall syndrome severity relative to oral exposure via cereals. No significant differences were observed by substituting peanut oil for water as a vehicle for i.p. administered TMDT. In conclusion, high vs low fat food can differentially affect TMDT onset of action, probably due to differences in availability from the gastrointestinal tract. These results should be considered when searching for effective treatments for TMDT poisoning.
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Tetramethylenedisulfotetramine: A Health Risk Compound and a Potential Chemical Warfare Agent. TOXICS 2018; 6:toxics6030051. [PMID: 30135374 PMCID: PMC6160919 DOI: 10.3390/toxics6030051] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 08/04/2018] [Accepted: 08/16/2018] [Indexed: 01/03/2023]
Abstract
Tetramethylenedisulfotetramine (TETS, tetramine) is a toxic organic compound that is used as an effective rodenticide. However, this neurotoxin is not only toxic to rodents, it also causes poisoning in humans. Due to its high level of toxicity for humans, the use of TETS as a rodenticide has been banned and its production has been discontinued. Despite this, human poisoning by this substance is unfortunately still very common. The largest number of poisonings are reported in China, but in the United States, dozens of poisonings still happen annually. TETS is one of the most hazardous pesticides and also a possible chemical warfare agent with no known antidote. In this article, we aim to summarize the biochemical and toxicological data of TETS and hope to cast some light on the toxicological risk to human health.
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Behavioral toxicity of sodium cyanide following oral ingestion in rats: Dose-dependent onset, severity, survival, and recovery. Food Chem Toxicol 2018; 114:145-154. [PMID: 29454866 DOI: 10.1016/j.fct.2018.02.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 02/02/2018] [Accepted: 02/14/2018] [Indexed: 11/22/2022]
Abstract
Sodium cyanide (NaCN) is a commonly and widely used industrial and laboratory chemical reagent that is highly toxic. Its availability and rapid harmful/lethal effects combine to make cyanide a potential foodborne/waterborne intentional-poisoning hazard. Thus, laboratory studies are needed to understand the dose-dependent progression of toxicity/lethality following ingestion of cyanide-poisoned foods/liquids. We developed an oral-dosing method in which a standard pipette was used to dispense a sodium cyanide solution into the cheek, and the rat then swallowed the solution. Following poisoning (4-128 mg/kg), overt toxic signs were recorded and survival was evaluated periodically up to 30 hours thereafter. Toxic signs for NaCN doses higher than 16 mg/kg progressed quickly from head burial and mastication, to lethargy, convulsions, gasping/respiratory distress, and death. In a follow-on study, trained operant-behavioral performance was assessed immediately following cyanide exposure (4-64 mg/kg) continuously for 5 h and again the following day. Onset of behavioral intoxication (i.e., behavioral suppression) occurred more rapidly and lasted longer as the NaCN dose increased. This oral-consumption method with concomitant operantbehavioral assessment allowed for accurate dosing and quantification of intoxication onset, severity, and recovery, and will also be valuable in characterizing similar outcomes following varying medical countermeasure drugs and doses.
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