Effects of Malathion on the Ultrastructure and the Acetylcholinesterase Activity of the Developing Spinal Cord in Chick Embryos

Malathion이 발생중(發生中)인 개배(鷄胚) 척수(脊髓)의 미세구조(微細構造)와 acetylcholinesterase 활성(活性)에 미치는 영향(影響)

  • Kim, Wan-Jong (Dept. of Biology, Wonju College of Medicine, Yonsei University) ;
  • Deung, Young-Kun (Dept. of Biology, Wonju College of Medicine, Yonsei University) ;
  • Choe, Rim-Soon (Dept. of Biology, College of Science, Yonsei University)
  • 김완종 (연세대학교 원주의학대학 생물학교실) ;
  • 등영건 (연세대학교 원주의학대학 생물학교실) ;
  • 최임순 (연세대학교 이과대학 생물학과)
  • Published : 1988.05.01

Abstract

Chick embryos which have received a single injection of the organophosphate compound, malathion (0.1 mg/0.05 ml, 0.5 mg/0.05 ml, 1.0 mg/0.05 ml or 2.0 mg/0.05 ml) via the yolk sac at certain times (2 days, 4 days or 6 days after incubation) have been investigated. After 9 days of incubation, chick embryos were harvested to examine the effects of malathion on the ultrastructure and the acetylcholinesterase(AChE) activity of the developing spinal cord. The effects of simultaneous injection of malathion and nicotinamide were also compared. On ultrastructural findings, neurons in the ventral horn of spinal cord showed to be inhibited in their differentiation by malathion; nuclear irregularity, separation of nuclear membranes, reduction of ribosomal distribution, and cytoplasmic vacuoles were observed. In the younger embryos treated with relatively high doses of malathion, nucleus and cytoplasmic organelles of neurons were severely destroyed, and the neurons were shown to be necrotic. On cytochemical study of AChE by electron microscope, the positive reaction products of AChE were localized at the membranes of nucleus and endoplasmic reticulum of neurons. Inhibition of AChE activity was severe in groups treated with relatively low doses of malathion. Nicotinamide (5.0 mg/0.05 ml) alleviated malathion-induced morphological alterations. In conclusion, it is suggested that malathion changes the ultrastructure and reduces. AChE activity in differentiating neurons, and the severity of which is consistently dose- and age-dependent.

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