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

Abstract

The histochemical changes occurring in association with the development of acute and subacute myopathy have been studied in the rat diaphragm 30 min-48 h after a single i.p. injection of 1.82 mg/kg of the irreversible cholinesterase inhibitor organophosphate, diisopropylfluorophosphate (DFP). In addition to a considerable inhibition of the AChE activity of the motor end-plates, accumulation of ionic Ca2+ and an increase in neutral protease activity in the subjunctional sarcoplasm have been demonstrated. A temporal and causal relationship has been established between the histochemical changes and the development of the ultrastructural signs of myopathy.