Model establishment and injury assessment of chlorpyrifos dynamic-inhalation of rats / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE To establish a model for chlorpyrifos(CPF)whole-body dynamic inhalation exposure in SD rats and investigate the injury effects after acute exposure by CPF. METHODS By optimizing the aerosol parameters ,the animal acute dynamic inhalation exposure of CPF was established. Absorption sampling-gas phase detecting technology was used to monitor the concentration of CPF in the whole-body dynamic-inhalation exposure cabin by exploring the relationship between the concentration , particle size of CPF aerosol and the CPF inhalation time in the exposure cabin via a particle size detector. Using Bliss method,specific pathogen free SD male rats were allocated to the environment of CPF exposure at different lethal concentrations and time points. The symptoms and deaths of these SD male rats in different groups were recorded within the following 10 d. Based on the median lethal concentra?tion time(LCt50),the values of plasma cholinesterase(ChE)were checked at different time points after being exposed at different doses. RESULTS The mean concentrations of CPF aerosol at nine time points was 160.6 mg · m-3,the relative standard deviation value was 6.9%;the geometrical mean of aerosol particle size was 1.1 μm,and the geometric standard deviation was 1.8. The results met the technical requirements of Organization for Economic Cooperation and Development regarding acute inhalation exposure. Under these equipment conditions,the LCt50 of CPF acute inhalation of SD male rats was 1654.2 mg · m-3 · h,suggesting that plasma ChE inhibitory rate was higher with the increase in the exposing dose,and that there was a significant difference as compared with the controls(P<0.05). CONCLU?SION The model for whole-body dynamic-inhalation exposure of CPF is applicable to rats,which can serve as an experimental platform and technical support to inhalation vulnerability and the research on prevention and cure of organophosphate industrial products and nerve agents.