Effects of subchronic inhalation exposure to an organophosphorus insecticide compound containing dichlorvos on wistar rats’ otoacoustic emissions

Reis, Aléxia dos; Cunha, Eduarda Oliveira; Valle, Marina Tuerlinckx Costa; Machado, Márcia Salgado; Dallegrave, Eliane

doi:10.1016/j.bjorl.2020.04.005

Cited by 5 publications

(6 citation statements)

References 35 publications

(34 reference statements)

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“…The similarity between the amplitude variations (final minus initial) between the association group and the cisplatin group (p <0.05, Kruskal Wallis) also indicates that the pesticides tested in association are comparable to the ototoxic drug (positive control). Regarding this variation, the decrease in the association group compared to the control at 8 kHz on the right and 6 and 8 kHz on the left ear (p <0.05, Kruskal Wallis; p <0.05, Dunn's post hoc), and its similarity with the positive control group is congruent with previous studies that evaluated DPOAEs before and after exposure to dichlorvos 9 and cypermethrin 10 alone in Wistar rats. The exposure to cypermethrin generated a reduction in the amplitude variation in 10 and 12 kHz on the right and in 8, 10 and 12 kHz on the left.…”

Section: Discussionsupporting

confidence: 88%

“…The experimental protocol was based on previous studies 9,10 . The animals included in the experimental protocol had distortion product otoacoustic emissions (DPOAE) present in the frequencies of 4, 6, 8, 10 and 12 kHz.…”

Section: Methodsmentioning

confidence: 99%

“…Inhalation exposure chambers acoustically treated by an enclosure (avoiding noise) were coupled to ultrasonic nebulizers as an inlet stream and as an exhaust system an aspirator was coupled to the chambers. Each chamber had 56 L of volume and accommodated 4 animals following the volume proposed by the OECD 9,13 . To determinate the sample size, a previous research 14 that evaluated rats exposed to cisplatin, an ototoxic substance, was analyzed and considered.…”

Section: Methodsmentioning

confidence: 99%

“…Its mechanism of action involves blocking nerve conduction, persistent depolarization, reduction of the action potential amplitude and depolarization in axonal conduction. There is also a suppression of chloride channels related to the GABA receptor [9][10][11][12] . In isolation, both substances caused hearing damage in Wistar rats exposed sub-chronically by inhalation.…”

Section: Introductionmentioning

confidence: 99%

“…In isolation, both substances caused hearing damage in Wistar rats exposed sub-chronically by inhalation. The choice of the sub-chronic route in studies that evaluate the toxicity of pesticides is essential, since this is a frequent route of intoxication in humans and animals associated with numerous cases of chronic or sub-chronic exposure 9,10 .…”

Section: Introductionmentioning

confidence: 99%

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Ototoxicity of an association of insecticides compounds containing dichlorvos and cypermethrin in Wistar rats

et al. 2022

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Purpose: to evaluate possible ototoxicity secondary to exposure to a combination of pesticides (dichlorvos and cypermethrin based insecticides). Methods: the Wistar rats were divided into 3 groups (12 animals per group): control (water), positive control for hearing damage (cisplatin) and experimental (exposed to dichlorvos and cypermethrin). The amplitude of distortion product otoacoustic emissions was assessed before and after the exposure. Systemic toxicity signs were also evaluated (clinical signs, weight gain and plasma cholinesterase). Wilcoxon test analyzed the post-exposure amplitudes compared to pre-exposure and Kruskal Wallis following Dunn's post hoc tests analyzed the amplitudes' variation. Normally distributed variables were evaluated by Student's t test. Results: body weight and plasma cholinesterase values were similar comparing the pre and post exposure in the experimental group. The control group did not manifest significant amplitude reduction of otoacoustic emissions between the pre and post evaluation. In the group exposed to cisplatin there was a significant reduction in amplitudes at 12 kHz on the right (p = 0.006; Wilcoxon) and 4 kHz on the left (p = 0.032; Wilcoxon). In the group exposed to pesticides, there was a significant reduction in the right ear at 4 kHz (p = 0.034; Wilcoxon) and 8 kHz (p = 0.019; Wilcoxon) and in the left ear at 4 kHz (p = 0.007; Wilcoxon), 6 kHz (p = 0.023; Wilcoxon), 8 kHz (p = 0.045; Wilcoxon) and 12 kHz (p = 0.028; Wilcoxon). Conclusion: there was ototoxicity in the experimental group, without a relevant systemic toxicity.

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Section: Discussionsupporting

confidence: 88%

Section: Methodsmentioning

confidence: 99%