ORGANOPHOSPHATE MYOTOXICITY

Organophosphates comprise a group of chemical compounds extensively us ed in farming as insecticides, which cause accidental poisoning in ani mals and men and are also used in suicide attempts. The toxicity of th ese compounds is due especially to the cardiac and respiratory impairm ent in consequence of autonomic nervous system disorders. However it i s known that some of these products induce a myopathy in experimental animals and humans. This myopathy is characterized by muscle cell dege neration, involving above all the respiratory muscles. Based on the fa ct that this involvement certainly enhances the respiratory impairment , this study offers an experimental method for routine evaluation of o rganophosphate myotoxicity, using a minimal and sufficient battery of stains and histochemical reactions, for muscle necrosis quantification . For this purpose, albino vats (Wistar) treated with the organophosph ate paraoxon, were used both with and without antidotes (atropine or p ralidoxime). Muscle fiber necrosis in the diaphragm of the rats treate d with paraoxon or paraoxon and atropine, that affected about 15% of t he fibers in some areas, was detected In the group treated with paraox on and pralidoxime, a minimal necrosis was seen, revealing a protectiv e role of this later antidote during the development of myopathy.