Central Neurophysiological Changes Caused by Combined Treatment with Environmental Xenobiotics in Rats

László Nagymajtényi, András Papp, and Tünde Vezér

Department of Public Health, University of Szeged, Szeged, Hungary

Corresponding author: László Nagymajtényi
    Department of Public Health
    University of Szeged
    Dóm tér 10
    H-6720 Szeged, Hungary
    Telephone: +36-62-545-119
    Fax number: +36-62-545-120
    E-mail: nml@puhe.szote.u-szeged.hu

CEJOEM 2004, Vol.10. No.1.: 4651

Key words:
Electrocorticogram, pesticide, heavy metal, rat

Nowadays, the population mostly undergo multiple exposition to various chemical compounds. In our previous experiments aimed at modelling human exposure to pesticides and heavy metals, it was found that combinations like pesticide+pesticide or metal+metal caused different functional alterations of the nervous system than the administration of single compounds did. The aim of this study was to analyse the changes in certain central neurofunctional parameters caused with combined treatment by low doses of three xenobiotics. The animals were given the substances (pesticide+pesticide+pesticide, or metal+metal+metal) in different stages of the intra- and extrauterine development. The doses, given by gavage, were 7.0 or 28.0 mg/kg dimethoate, 4.3 or 17.0 mg/kg propoxur, 5.4 or 21.6 mg/kg cypermetrine and 80.0 or 320.0 mg/kg lead, 0.4 or 16 mg/kg mercury, 3.5 or 14.0 mg/kg of cadmium (in form of C4H6O4Pb, HgCl2, CdCl2, respectively). The neurophysiological function investigated was the spontaneous activity of the brain (electrocorticogram) in the somatosensory, visual, and auditory areas. The results showed that, compared to the alterations caused by combinations of two pesticides or metals, the changes to three xenobiotics seemed to be more marked or even significant. The neurophysiological alterations found point to increased risk to simultaneous exposure to different environmental xenobiotics.

Received: 19 September 2003
Accepted: 1 December 2003

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