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AGING-RELATED CARBARYL EFFECTS IN BROWN NORWAY RATS
JAREMA, K., P. M. Phillips, AND R. C. MACPHAIL. AGING-RELATED CARBARYL EFFECTS IN BROWN NORWAY RATS. Presented at Society of Toxicology 49th annual meeting, Salt Lake City, UT, March 07 - 11, 2010.
As part of a larger research program on life-stage susceptibility, this experiment determined the effect of the carbamate pesticide carbaryl on the locomotor activity of adolescent, young-adult, middle-age and senescent male Brown Norway rats.
The rapid increase in older adults in the population highlights the importance ofunderstanding the role of aging in susceptibility to environmental contaminants. Aspart of a larger research program on life-stage susceptibility, this experiment determined the effect of the carbamate pesticide carbaryl on the locomotor activity of adolescent, young-adult, middle-age and senescent male Brown Norway rats. Locomotion was evaluated during 30-min sessions in photocell devices that recorded both horizontal and vertical activity. Carbaryl (17 mglkg) and com-oil vehicle were administered p.o. at varying times (30, 60, 120 and 240 min) prior to a test session. The rats were 1 mo (n=18), 4 mo (n=18), 12 mo (n=18) and 24 mo (n=14) at the beginning ofthe experiment. Each rat received both com oil and carbaryl at weekly intervals; treatment times were arranged in a mixed order. Following com-oil treatment, horizontal activity was highest in 4-month rats then decreased at older ages. Vertical activity generally decreased with age. Except for the 240-min treatment time, carbaryl decreased both horizontal and vertical locomotor activity in all rats. Carbaryl effects were next expressed as a percentage ofeach rat's vehicle response then averaged across rats in each age group. Carbaryl produced proportionately greater effects in older rats. Older rats also took longer to recover following carbaryl treatment. results demonstrate the importance of assessing toxicant effects across a range of ages, from adolescence to senescence, in order to make informed estimates of risk. These results also indicate aging may increase susceptibility to environmental contaminants. (This abstract does not necessarily reflect USEPA policy.)