A LIGHT AND ELECTRON MICROSCOPIC HISTOCHEMICAL STUDY ON THE MECHANISM OF DFP‐INDUCED ACUTE AND SUBACUTE MYOPATHY

Abstract
Histochemical changes occuring in association with the development of acute and subacute myopathy were studied in the rat diaphragm 30 min to 48 h after a single i.p. injection of 1.82 mg/kg of the irreversible cholinesterase inhibitor organophosphate [insecticide] DFP. In addition to a considerable inhibition of the AChE [acetylcholinesterase] activity of the motor end-plates, accumulation of ionic Ca2+ and increased neutral protease activity in the subjunctional sarcoplasm were demonstrated. A temporal and causal relationship was established between the histochemical changes and the development of the ultrastructural signs of myopathy.