Cytotoxic effects of permethrin in oocytes of Rhipicephalus sanguineus (Acari: Ixodidae) fully engorged females: I. Direct or indirect action of the acaricide in germ cells?

Autor(es)

Roma, Gislaine Cristina ^[1] ; Scopinho Furquim, Karim Christina ^[2] ; Bechara, Gervasio Henrique ^[2] ; Camargo Mathias, Maria Izabel ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, Inst Biociencias, Dept Biol, UNESP, BR-13506900 Rio Claro, SP - Brazil

^[2] UNESP, Fac Ciencias Agr & Vet, Dept Patol Vet, BR-14884900 Jaboticabal, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Experimental and Applied Acarology; v. 53, n. 3, p. 287-299, MAR 2011.
• Citações Web of Science: 15

Resumo

Given the wide use of synthetic chemicals to control ticks, this study evaluated the effects of the permethrin pyrethroid on oocytes of Rhipicephalus sanguineus fully engorged females in order to examine whether this compound, in addition to the proven neurotoxic effect, also acts directly on germ cells. The results revealed that permethrin effectively inhibits and/or interrupts the reproductive process of R. sanguineus. Exposed oocytes exhibited prominent structural changes such as altered shape of cells and germ vesicle (oocyte nucleus), cytoplasmic vacuolation, and decrease of yolk granules. The composition of the latter, however, was not altered. These findings confirm those already reported by Roma et al. (Food Chem Toxicol 48:825-830, 2010) demonstrating that permethrin acts on germ cells of R. sanguineus via direct absorption from the hemolymph by pedicel cells, or by the oocyte plasmic membrane. On the other hand, these results contradict studies reporting that acaricides act exclusively on the nervous systems of ticks and that all the changes in other organs are a result from the indirect action of these chemical compounds, because blocking of the nervous system would compromise the normal metabolism of other organs (dependent on sensory information). (AU)

• Processo FAPESP: 07/57809-5 - Estudo morfológico dos ovários de carrapatos Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) e do sangue periférico de camundongos, ambos submetidos ao piretróide permetrina (ingrediente ativo do Advantage Max3, Bayer)
• Beneficiário: Gislaine Cristina Roma
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 07/59020-0 - Estudo da morfo-histologia externa e interna (sistemas: salivar, produtivo e digestório) de três espécies de carrapatos de importância médica veterinária (Acari - Ixodidae)
• Beneficiário: Maria Izabel Souza Camargo
• Modalidade de apoio: Auxílio à Pesquisa - Regular