title: Morphological analysis of the vestibular system of guinea pigs poisoned by organophosphate.
abstract: BACKGROUND
  The vestibular system is responsible for body balance. There are substances that damage it, causing dizziness; these are termed vestibulotoxic substances. Agrochemicals have been investigated for ototoxicity because of studies that identified dizziness as a recurrent symptom among rural workers' complaints.
  
  
  OBJECTIVE
  To histopathologically evaluate the vestibular system in guinea pigs exposed to an organophosphate, and to identify the drug's effects on this system.
  
  
  METHODS
  Experimental clinical study. Eighteen guinea pigs were used; six of them poisoned with the organophosphate chlorpyrifos at doses of 0.5mg/kg/day and seven of them at 1mg/kg/day; and a control group of five guinea pigs was exposed to distilled water, all for 10 consecutive days. Later, ciliary tufts of saccule and utricle maculae were counted by scanning electron microscopy.
  
  
  RESULTS
  Comparing the groups, a one-way ANOVA test for the variable "saccule" (p=0.0569) and a Kruskal-Wallis test for the variable "utricle" (p=0.8958) were performed, revealing no difference among groups in both variables.
  
  
  CONCLUSIONS
  The histopathologic analysis of the vestibular system of guinea pigs exposed to an organophosphate showed no difference in the amount of ciliary tufts of saccule and utricle maculae at the doses tested, although the result for the variable "saccule" was considered borderline, showing a trend for significance.
authors.affiliation: Department of Physiotherapy, Universidade Federal do Pampa (UNIPAMPA), Rio Grande do Sul, RS, Brazil. Electronic address: liciacogo@hotmail.com.
authors.forename: Lícia Assunção
authors.initials: LA
authors.lastname: Cogo
authors.affiliation: Department of Medicine, Sciences of Rehabilitation Program, Universidade de São Paulo (USP), São Paulo, SP, Brazil; Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brazil.
authors.forename: Valdete Alves Valentins dos
authors.initials: VA
authors.lastname: Santos Filha
authors.affiliation: Department of Biology, Postgraduate Program in Ophthalmology, Otolaryngology, and Head and Neck-Shoulder, Universidade de São Paulo (USP), Ribeirão Preto, SP, Brazil; Department of Ophthalmology, Otolaryngology, and Head and Neck-Shoulder, Universidade de São Paulo (USP), Ribeirão Preto, SP, Brazil.
authors.forename: Adriana de Andrade Batista
authors.initials: Ade A
authors.lastname: Murashima
authors.affiliation: Department of Medical Sciences, Universidade de São Paulo (USP), Ribeirão Preto, SP, Brazil; Department of Ophthalmology, Otolaryngology, and Head and Neck-Shoulder, Universidade de São Paulo (USP), Ribeirão Preto, SP, Brazil.
authors.forename: Miguel Angelo
authors.initials: MA
authors.lastname: Hyppolito
authors.affiliation: Department of Veterinary Medicine, Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brazil; Department of Morphology, Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brazil.
authors.forename: Aron Ferreira da
authors.initials: AF
authors.lastname: Silveira
mesh_terms: D000818:Animals; D003051:Cochlea / Q000187:drug effects* / Q000473:pathology; D004195:Disease Models, Animal; D006168:Guinea Pigs; D007306:Insecticides / Q000633:toxicity*; D008297:Male; D009946:Organothiophosphorus Compounds / Q000633:toxicity*; D014722:Vestibule, Labyrinth / Q000187:drug effects* / Q000473:pathology
chemical_list: D007306:Insecticides; D009946:Organothiophosphorus Compounds
keywords: Equilíbrio postural; Insecticides organophosphate; Inseticidas organofosforados; Pesticides; Postural balance; Praguicidas; Toxicidade; Toxicity; Vestibule labyrinth; Vestíbulo do labirinto