title: Developmental neurotoxicity of monocrotophos and lead is linked to thyroid disruption.
abstract: OBJECTIVE
  A role of thyroid disruption in developmental neurotoxicity of monocrotophos (MCP) and lead is studied.
  
  
  METHODS
  A total of 24 female rats after conception were randomized into four groups of six each and treated as follows: Group I - Sham was administered distilled water orally. Group II - A positive control was administered methyl methimazole at 0.02% orally in drinking water. Group III - MCP orally at 0.3 mg/kg and Group IV - Lead acetate at 0.2% orally in drinking water. The drug was administered from gestation day 3 through post-natal day 21 in all the groups. Acetylcholinesterase (AChE) inhibition, thyroid profile (thyroid stimulating hormone, T3 and T4), neurodevelopment (brain wet weights, DNA, RNA and protein), and neurobehavioral (elevated plus maze, photoactometry, and Morris water maze) parameters were assessed in pups. A histopathology of thyroid of dams and brain of progeny was conducted.
  
  
  RESULTS
  Inhibition of AChE was <20%. Thyroid profile decreased in the treatment groups. Neurodevelopmental and neurobehavioral parameters did not reveal any significant changes. Thyroid architecture was affected significantly with MCP and lead. Cortical layers too were affected. The three layers of cerebellum either had abnormal arrangement or decreased cellularity in all treated groups relating to thyroid disruption.
  
  
  CONCLUSIONS
  MCP and lead might have affected the development of cerebrum and cerebellum via thyroid disruption leading to developmental neurotoxicity.
authors.affiliation: Department of Veterinary Pharmacology & Toxicology, College of Veterinary Science, Sri P.V. Narsimha Rao Telangana State University for Veterinary, Animal and Fishery Science, Hyderabad - 500 030, Telangana, India.
authors.forename: B Kala
authors.initials: BK
authors.lastname: Kumar
authors.affiliation: Department of Veterinary Pharmacology & Toxicology, College of Veterinary Science, Sri P.V. Narsimha Rao Telangana State University for Veterinary, Animal and Fishery Science, Hyderabad - 500 030, Telangana, India.
authors.forename: A Gopala
authors.initials: AG
authors.lastname: Reddy
authors.affiliation: Department of Bio-technology, Ministry of Science & Technology, New Delhi, India.
authors.forename: A Vamsi
authors.initials: AV
authors.lastname: Krishna
authors.affiliation: Department of Pathology, National Institute of Nutrition (ICMR), Hyderabad, Telangana, India.
authors.forename: S S Y H
authors.initials: SS
authors.lastname: Quadri
authors.affiliation: Sri P.V. Narsimha Rao Telangana State University for Veterinary, Animal and Fishery Science, Hyderabad - 500 030, Telangana, India.
authors.forename: P Shiva
authors.initials: PS
authors.lastname: Kumar
keywords: behavioral alterations; developmental neurotoxicity; lead; monocrotophos; thyroid disruption