Failure of Intravenous Lipid Emulsion to Reduce Diazinon-induced Acute Toxicity: a Pilot Study in Rats

Diazinon (DZN) is a synthetic organophosphorus (OPs) insecticide widely used in agricultural and household applications. OPs, particularly DZN, are highly lipid soluble liquids. Intravenous lipid emulsion (ILE) has been shown to reduce toxicity caused by some lipid soluble agents. We evaluated the antidote effect of ILE on acute toxicity of DZN. Twenty-four Sprague-Dawley female rats weighting 200-250 g were treated orally with dose of 480 mg/ kg of DZN gavaged at the volume of 0.5 mL/kg. Thirty minutes after administration of DZN, two groups were treated by either ILE 10% (ILE10) or normal saline (NS) (16 mL/kg) (NS16) that were infused for the duration of 15 minutes. Another two groups were also treated by either ILE 20% (ILE20) or NS (10 mL/kg: NS10) as above. The changes in body weight, diarrhea score, muscular power, fasciculation, convulsions and mortality rate of the animals were all monitored immediately after infusions and then every 6 h up to 48 h. There was no significant difference in animals mean weight between different groups during the observation period. In addition, during the 48-hour observation we could not find any difference in muscular power and diarrhea score between groups of ILE20-NS10 and ILE10-NS16 in comparison with each other, and neither ILE 10% nor ILE %20 could not reduce mortality rate of animals or increase the survival time of rats. In conclusion, ILE seems to be unable to reverse DZN acute toxicity and it might be due to conversion of DZN to potent and less lipid soluble agent.