The acute toxicity of Paraquat in mice

OBJECTIVE To explore the acute toxicity of Paraquat(PQ) in mice and calculate its 50% lethal dose(LD50).METHODS Different doses of PQ were orally given to mice.The movement and the toxic symptoms were observed,and the number of death of mice was recorded.The LD50 was calculated with probability units method.RESULTS The times of movement of mice were reduced after PQ was given.Before death,the respiratory rate of mice increased,accompanied with gasping breath and flapping of masal alae.The death peak time was within 2 h and the cause of death was multiple organ failure syndrome(MOFS). The values of PQ LD50 in male and female mice were 106.99 mg·kg-1(97.01-118.03 mg·kg-1) and 86.40 mg·kg-1(74.54-100.14 mg·kg-1),respectively.CONCLUSION PQ is a pesticide with moderate toxicity.The female mice are more sensitive to the toxicity of PQ.