Evidence for a separate mechanism of toxicity for the Type I and the Type II pyrethroid insecticides

Breckenridge, Charles B.; Holden, Larry R.; Sturgess, Nicholas C.; Weiner, Myra L.; Sheets, Larry P.; Sargent, Dana; Soderlund, David M.; Choi, Jin-Sung; Symington, S.B.; Clark, J. Marshall; Burr, Steven W.; Ray, David

doi:10.1016/j.neuro.2009.09.002

Cited by 179 publications

(134 citation statements)

References 38 publications

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“…Type I pyrethroids (which do not contain a cyano group on the α carbon atom) provoke the T (tremor) syndrome, while Type II pyrethroids (which contain a cyano group on the α carbon atom) cause choreoathetosis and salivation (CS syndrome). Traditionally, esfenvalerate belongs to the Type II group, but according to more recent studies, it has rather mixed Type I/II characteristics [12]. In our study, the animals that developed intoxication symptoms displayed first tremor and salivation, then writhing convulsions, so we observed all known acute signs of pyrethroid poisoning, reflecting nervous system hyperexcitation.…”

Section: Discussionsupporting

confidence: 55%

Nervous System and Gastrointestinal Effects of the Insecticide Esfenvalerate on the Rat: An <i>Ex Vivo</i> Study

Varró¹,

Szabó²,

Kovács³

et al. 2014

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Esfenvalerate belongs to the pyrethroid group of insecticides which display significant selective toxicity against insects compared to mammalian species, nevertheless, they may pose health risks, especially in case of accidental exposure. The aim of the present study was to model the effect of acute, relatively high-dose exposure of the esfenvalerate-containing formulation Sumi-Alpha ® . Eventual functional alterations in the central nervous system and in the gastrointestinal tract were studied on in vitro tissue preparations at different delays after intragastric administration to rats. Neuronal effects were characterized by field potential recording in cortical and hippocampal brain slices, while gastrointestinal effects were examined by analyzing the motility and excitability of isolated ileum segments. On the brain slices originating from esfenvalerate-treated animals, changes in excitability of both inhibitory and excitatory type could be observed. Voltage thresholds necessary to evoke responses in neocortex slices were elevated, and population spike amplitudes were lower in hippocampal slices. However, epileptiform potentials with pronounced late components were also observed. A decreased long-term potentiation (LTP) could be seen in both brain areas after esfenvalerate treatment. Seizure susceptibility of the slices was not significantly altered, but tended to be somewhat higher in slices originating from treated rats. In ileum segments, both spontaneous and acetyl-choline (ACh)-elicited contractions were modified by treatment. Esfenvalerate raised the amplitude of contractions in the low ACh concentration range. However, the solvent xylene also considerably contributed to the detected changes. We can conclude that a relatively high, single oral dose of Sumi-Alpha ® exerted mild and temporary effects on the elementary brain functions and intestine functions of the rat. *Corresponding author. P. Varró et al.366

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Section: Discussionsupporting

confidence: 55%

Nervous System and Gastrointestinal Effects of the Insecticide Esfenvalerate on the Rat: An <i>Ex Vivo</i> Study

Varró¹,

Szabó²,

Kovács³

et al. 2014

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“…These uncertainties regarding pyrethroid actions on VGCC function confound a better understanding of how effects on VGCCs may contribute to pyrethroid acute neurotoxicity (Shafer and Meyer, 2004). It has been proposed that, in addition to actions on VGSC, pyrethroid effects on VGCC may constitute a separate key initiating event in pyrethroid neurotoxicity (Soderlund et al, 2002;Breckenridge et al, 2009). Thus, the extent to which actions of pyrethroids on VGCC observed in non-neuronal/ nonmammalian or subcellular fractions can be replicated in intact neurons will inform the robustness of proposed modes of action involving direct effects on VGCC.…”

Section: Introductionmentioning

confidence: 99%

Mechanisms of Pyrethroid Insecticide-Induced Stimulation of Calcium Influx in Neocortical Neurons

Cao¹,

Shafer

Murray³

2010

J Pharmacol Exp Ther

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Pyrethroid insecticides bind to voltage-gated sodium channels (VGSCs) and modify their gating kinetics, thereby disrupting neuronal function. Pyrethroids have also been reported to alter the function of other channel types, including activation of voltage-gated calcium channels. Therefore, the present study compared the ability of 11 structurally diverse pyrethroids to evoke Ca 2ϩ influx in primary cultures of mouse neocortical neurons. Nine pyrethroids (tefluthrin, deltamethrin, -cyhalothrin, ␤-cyfluthrin, esfenvalerate, S-bioallethrin, fenpropathrin, cypermethrin, and bifenthrin) produced concentration-dependent elevations in intracellular calcium concentration (

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“…En el caso de los piretroides tipo I, éstos producen un síndrome de intoxicación T, que se caracteriza por temblores, hiperexcitabilidad y ataxia locomotriz. En contraste, los piretroides tipo II, provocan el síndrome C, donde se presenta coreo atetosis y salivación (Breckenridge et al 2009). En este contexto, la bifentrina es un piretroide tipo I que altera los canales de sodio en las terminales de las células nerviosas para despolarizar el funcionamiento pre sináptico (de Moraes et al 2013).…”

Section: Discussionunclassified

TOXICIDAD AGUDA DIFERENCIAL DE TALSTAR® (BIFENTRINA) Y BIOTHRINE® (DELTAMETRINA) EN LA TILAPIA NILÓTICA Oreochromis niloticus

Gío

Sánchez

Meza

et al. 2018

Rev. Int. Contam. Ambie.

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Palabras clave: acuacultura, insecticidas, peces, CL50, dengue, ecotoxicología RESUMENLa tilapia Oreochromis niloticus es una especie de importancia en acuacultura con un desarrollo promisorio en la península de Yucatán. La bifentrina y la deltametrina son dos piretroides ampliamente utilizados por el sector salud en Yucatán para el control del mosquito Aedes aegypti, vector del dengue. Se evaluó la toxicidad aguda diferencial de Talstar® (sustancia activa, bifentrina) y Biothrine® (principio activo, deltametrina), en juveniles de tilapia O. niloticus. Se usaron ocho concentraciones de Talstar® (2.5 -400 µg/L) y ocho concentraciones de Biothrine® (0.56 -112 µg/L), más un testigo sin insecticida y tres repeticiones por tratamiento. Los signos de toxicidad en los peces bajo la influencia de ambos insecticidas fueron: nadadas erráticas, desbalance e hiperventilación, aunque resultaron más evidentes y en un menor tiempo de aparición, en las concentraciones más altas. El análisis probit reveló que la concentración letal media (CL50) de Talstar® fue de 75.11 µg/L a las 96 horas con intervalos de confianza (95 %) de 58.76 (inferior) y 96.34 (superior) µg/L. La CL50 de Biothrine® fue de 28.36 µg/L a las 96 horas, con intervalos de 23.29 y 35.27 µg/L. Estos valores son considerados como extremadamente tóxicos y alertan por el efecto contaminante potencial que podrían producir en ambientes naturales y de acuacultura. Es necesario continuar con la evaluación de los mecanismos de toxicidad de insecticidas que son utilizados en el sector salud para especies de importancia acuícola en México. Lo anterior por la perspectiva de continuar con su empleo y por el desarrollo del sector en la península de Yucatán.Key words: aquaculture, insecticides, fishes, LC50, dengue, ecotoxicology ABSTRACT Tilapia, Oreochromis niloticus is an aquacultural important species and both, bifenthrin and deltamethrin are two synthetic pyrethroids used by Health Services in Yucatán to control Aedes aegypti mosquito, dengue's vector. Differential acute toxicity of Talstar® Rev. Int.

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Evidence for a separate mechanism of toxicity for the Type I and the Type II pyrethroid insecticides

Cited by 179 publications

References 38 publications

Nervous System and Gastrointestinal Effects of the Insecticide Esfenvalerate on the Rat: An <i>Ex Vivo</i> Study

Nervous System and Gastrointestinal Effects of the Insecticide Esfenvalerate on the Rat: An <i>Ex Vivo</i> Study

Mechanisms of Pyrethroid Insecticide-Induced Stimulation of Calcium Influx in Neocortical Neurons

TOXICIDAD AGUDA DIFERENCIAL DE TALSTAR® (BIFENTRINA) Y BIOTHRINE® (DELTAMETRINA) EN LA TILAPIA NILÓTICA Oreochromis niloticus

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Evidence for a separate mechanism of toxicity for the Type I and the Type II pyrethroid insecticides

Cited by 179 publications

References 38 publications

Nervous System and Gastrointestinal Effects of the Insecticide Esfenvalerate on the Rat: An &lt;i&gt;Ex Vivo&lt;/i&gt; Study

Nervous System and Gastrointestinal Effects of the Insecticide Esfenvalerate on the Rat: An &lt;i&gt;Ex Vivo&lt;/i&gt; Study

Mechanisms of Pyrethroid Insecticide-Induced Stimulation of Calcium Influx in Neocortical Neurons

TOXICIDAD AGUDA DIFERENCIAL DE TALSTAR® (BIFENTRINA) Y BIOTHRINE® (DELTAMETRINA) EN LA TILAPIA NILÓTICA Oreochromis niloticus

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Nervous System and Gastrointestinal Effects of the Insecticide Esfenvalerate on the Rat: An <i>Ex Vivo</i> Study

Nervous System and Gastrointestinal Effects of the Insecticide Esfenvalerate on the Rat: An <i>Ex Vivo</i> Study