Article

Neurotoxic changes in cat neurohypophysis after single and multiple exposures to diisopropylfluorophosphate and soman*1

Department of Physiology and Pharmacology, College of Veterinary Medicine, Iowa State University, Ames, Iowa 50011 USA
Fundamental and Applied Toxicology 12/1985; 5(6):1087-1096. DOI: 10.1016/0272-0590(85)90144-7

ABSTRACT Fine structural changes in cat neurohypophysis have been studied after single and multiple parenteral sub-LD50 doses of the organophosphates diisopropylfluorophosphate (DFP) and pinacolyl methylphosphonofluoridate (soman). While a single sub-LD50 dose of DFP does not alter fine structure, multiple exposures result in degeneration of axons. Single as well as multiple sub-LD50 doses of soman cause dilation of axons with an accumulation of neurosecretory granulated vesicles (NGVs). Increased metabolic activity is suggested by the presence of well-developed Golgi complexes and increased amounts of endoplasmic reticulum in the pituicytes of treated animals. Direct and indirect actions of DFP and soman on neurohypophysial hormone release are discussed as putative mechanisms responsible for the morphological changes in the neurohypophysis.

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