Organophosphate-Induced Acetylcholinesterase Inhibition and Embryonic Retinal Cell Necrosis In Vivo in the Teleost (Oryzias latipes)

Details

• Personal Author:
  Hamm JT ; Hinton DE ; Wilson BW
• Description:
  Recent monitoring of the Sacramento-San Joaquin River system (CA) indicates that levels of the organophosphate pesticide, diazinon, exceed National Academy of Science guidelines and these levels result in toxicity in USEPA acute toxicity tests with Ceriodaphnia dubia. Since organophosphates (OPs) inhibit acetylcholinesterase (AChE), the present study examined the effects of diazinon on the embryonic nervous system of a model teleost, medaka, Oryzias latipes. Preliminary histological screens revealed limited retinal cell necrosis in control embryos with apparent increased necrosis in diazinon-exposed embryos. Subsequently, embryos were exposed to 1.8 x 10(-5), 4.4 x 10(-5), or to 8.8 x 10(-5) M diazinon and replicates were frozen for biochemical analysis or were fixed for histopathological analysis at days 3, 5, and 7 of development. Diazinon exposure significantly inhibited AChE activity within whole embryos and in homogenates of retinas from treated animals. Histological examination of embryos indicated that as the retina underwent differentiation into distinct cell layers, between days 5 and 7, small foci of necrotic cells became apparent within the inner nuclear layer and isolated individual pyknotic cells were observed in the ganglion layer. Quantification of foci of necrotic cells revealed that 8.8 x 10(-5) M diazinon increased number and area of these lesions. Enzyme histochemistry localized AChE activity to regions equivalent to sites of necrosis. Separate exposures of embryos to the OP, diisopropylphosphorofluoridate, produced large foci of necrotic cells at sites equivalent to those seen following diazinon exposure. [Description provided by NIOSH]
• Subjects:
  Biochemistry Chemistry Embryology Enzymes Histology Hypersensitivity Nervous System Nervous System Diseases Occupational Health Safety
• Keywords:
  Acetylcholinesterase Biochemical-analysis Biochemical-tests Cell-alteration Cell-biology Cell-damage Cell-function Chemical-analysis Chemical-hypersensitivity Chemical-inhibition Chemical-reactions Chemical-synthesis Diazo-compounds Embryopathology Embryotoxicity Enzymatic-disorders Enzymatic-effects Enzyme-activity Enzymology Exposure-levels Exposure-limits Histomorphology Histopathology Nervous-system Nervous-system-disorders Nervous-system-function Retinal-disorders

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• ISSN:
  0161-813X
• Document Type:
  Text
• Funding:
  Cooperative Agreement
• Genre:
  Journal Article
• Place as Subject:
  California ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  19
• Issue:
  6
• NIOSHTIC Number:
  nn:20033260
• Citation:
  Neurotoxicology 1998 Dec; 19(6):853-869
• Contact Point Address:
  J. T. Hamm, School of Veterinary Medicine, Department of Anatomy, Physiology, and Cell Biology, University of California, Davis 95616
• Federal Fiscal Year:
  1999
• Performing Organization:
  University of California - Davis
• Peer Reviewed:
  True
• Start Date:
  19900930
• Source Full Name:
  Neurotoxicology
• End Date:
  20020929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:5bd1e413cf291587e47a6b276166e4583cb424bb1b4c21bdeb8b37d611582f908af0317305683a5bcf2f454c2b73b8396bacdd0a059b375719e1494e0e2e3bb1
• Download URL:
  https://stacks.cdc.gov/view/cdc/188908/cdc_188908_DS1.pdf
• File Type:
  [PDF - 3.60 MB ]