Functional neurotoxic effects of combined oral administration of insecticides to rats during intra- and extrauterine development
Most of the modern insecticides act on the nervous system. Although there have been extensive lexicological studies with the agents themselves, knowledge of the consequences of combined effects is as yet insufficient. The aim of the present study was to record and analyze the alterations in the cort...
Saved in:
| Main Authors: | |
|---|---|
| Format: | Article |
| Published: |
2005
|
| Series: | HOMEOSTASIS IN HEALTH AND DISEASE : INTERNATIONAL JOURNAL DEVOTED TO INTEGRATIVE BRAIN FUNCTIONS AND HOMEOSTATIC SYSTEMS
43 No. 4 |
| Subjects: | |
| mtmt: | 1240508 |
| Online Access: | http://publicatio.bibl.u-szeged.hu/27665 |
| Summary: | Most of the modern insecticides act on the nervous system. Although there have been extensive lexicological studies with the agents themselves, knowledge of the consequences of combined effects is as yet insufficient. The aim of the present study was to record and analyze the alterations in the cortical electrical activity of rats treated with combinations of widely used insecticides during development. Three insecticides were used in 1/25LD 50 dose: dimethoate (DIM, an organophosphate), propoxur (PRP, a carbamate) and cypermethrin (CYP, a pyrethroid), given in double (DIM-PRP, DIM-CYP, PRP-CYP) and triple (DIM-PRP-CYP) combinations in the following manner: Daily by gavage, from day 5 to 15 during pregnancy (P protocol), or from day 5 to 15 during pregnancy + for 4 weeks of lactation (P+L protocol), or from day 5 to 15 during pregnancy + for 4 weeks of lactation + the male offspring (F1 generation) treated for further 8 weeks post-weaning (P+L+P protocol). The electrophysiological parameters were investigated in the F1 male offspring (10 animals per group) at their age of 12 weeks. General toxic effects were monitored by the animals' weight gain. - For electrophysiological recording, the rats' left hemisphere was exposed in urethane anaesthesia, and spontaneous and stimulus-evoked activity was recorded from the primary somatosensory, visual and auditory area. The effect on the spontaneous activity was moderate. In all treatments involving DIM, fast waves were relatively increased, with the strongest effect seen in the DIM-CYP group. In the DIM-PRP and DBVI-CYP combinations, the effect with the P treatment protocol was opposite to that obtained with P+L or P+L+P. Latency of the somatosensory evoke potential was significantly shortened by the PRP-CYP and DIM-PRP-CYP combination when given during both pre- and postnatal development. Latency of the visual evoked potential was significantly lengthened by all combinations, mostly irrespective of the timing of treatment. - These results emphasize the negative effect of environmental toxicants on the developing nervous system and show the need for further studies in combination toxicology. |
|---|---|
| Physical Description: | 179-183 |
| ISSN: | 0960-7560 |