A comparison of efficiency of lipid emulsion and conventional therapy (atropine-pralidoxime) on tissues of rats poisoned with methyl parathion

Every year, as a result of encountering high-dose pesticides with occupational reasons, accidental or deliberately (suicidal) situations, millions of poisoning cases and correspondingly thousands of deaths occur over the world. Use of lipid emulsions for treatment of poisoning caused by lipophilic agents has been discussed recently. In our study, it is intended to determine that whether effectiveness of the atropine-pralidoxime treatment for the rats intoxicated with methyl parathion, which is one of the lipophilic agents that shows some tissue and biochemical changes in using of lipid emulsion. The experimental process of our study was conducted in Baskent University Center for Research and Production of Laboratory Animals with the continous efforts of 2 clinicians, 3 veterinarians and 2 technicians. 21 Sprague-Dawley rats divided into 3 equal groups. For first group methyl parathion, for second group at first methyl parathion then atropine and pralidoxime; for third group firstly methyl parathion, then lipid emulsion and later atropine and pralidoxime have been used. Fasciculation, convulsion, respiratory arrest and exitus of rats observed and meanwhile observed other clinical findings are noted. After 12 hours observation, rats received general anesthesia; thoracotomy was performed and rats sacrified by taking of intracardiac blood. Rats' level of pseudo cholinesterase enzyme activity determined from blood samples taken. Among 3 groups there is no statistically significant difference in terms of clinical findings and level of pseudo cholinesterase. After the sacrification, eight tissue samples taken by rats were examined under the electron microscope. It is determined that the extension in glia foots, participated in structure of blood-brain barrier in brain tissue, is significantly decreased in the group that lipid emulsion applied. This symptom is thought that lipid emulsion treatment will be a more effective method for the protection of structural integrity of the brain tissue in case of poisoning. Potentially, in a further study, which could be done with longer period/higher dose toxin, lipid emulsion will also be effective in reducing the cerebral toxic effects of organophosphate. In comparison with the atropine-pralidoxime treatment of bile canaliculus which are thought to cause methyl parathion poisoning in liver tissue, extension in disse space and decrease in microvillus, it is concluded that the lipid emulsion treatment is more effective treatment method. It is remarked that the gross edema in the connective tissue between pancreatic acini in the atropin-pralidoxim treatment group is less when compared with the control group. The edema is not observed in the lipit treatment group. This finding suggests lipid emulsion is more successfull in the treatment of edema caused by organophosphate poisoning. As a result, have less side effects and easily accessible agent, the effects of the lipid emulsion in liver and brain tissue, its constructive contribution to the improvement shown by this study. Lipid emulsion to treat organophosphate poisoning with the use of atropine-pralidoxime would be useful. Lipid emulsion is applied, if possible, should be applied to other drugs in different ways. Seem to benefit from selection of a wide vascular access for administration.