title: An in vitro approach to the evaluation of repeat exposure in the prediction of toxicity.
abstract: A strategy for the examination of repeat chronic exposure employed chemicals in the MEIC scheme. Repeat exposure to a non-cytotoxic concentration of certain chemicals leads to changes in sensitivity to a subsequent acute challenge. Six sequential exposures to 3T3-L1 cells, maintained in exponential growth, to ethylene glycol results in an enhanced resistance to cytotoxic damage from a subsequent challenge with 2-propanol. 2-propanol pre-exposure did not alter sensitivity to ethylene glycol. Ethanol or methanol pre-exposure reduces the apparent toxicity to a subsequent challenge with methanol or ethanol. Paracetamol or aspirin pretreatment reduces the toxic effects of paracetamol or aspirin. Hence, repeat exposure can result in a modulation of the cellular responses noted in vitro to cytotoxic concentrations of chemicals. This method demonstrates one approach to examining in vitro the relevance of chronic toxicity in vivo.
authors.affiliation: FRAME Alternatives Laboratory, Department of Human Anatomy and Cell Biology, University of Nottingham, Nottingham NG7 2UH, UK.
authors.forename: R H
authors.initials: RH
authors.lastname: Clothier
authors.forename: M
authors.initials: M
authors.lastname: Beed
authors.forename: R
authors.initials: R
authors.lastname: Samson
authors.forename: R
authors.initials: R
authors.lastname: Ward