title: Reactive oxygen species involvement in ricin-induced thyroid toxicity in rat.
abstract: Ricin is known to have diverse effects on the cells of different organs like liver, kidney, pancreas, intestines and parathyroid. Acute decrease in serum thyroid hormone level 24 h after ricin administration (1.5 micrograms/100 g) led us to suspect the toxic action of ricin on the thyroid. We monitored the lipid peroxidation (LP) and anti-oxidant status of the thyroid tissue to determine the role, if any, played by reactive oxygen species (ROS) in this pathology. An increase of 39% in LP and 47% in superoxide dismutase, along with a 8.5% decrease in catalase points to the imbalance in the antioxidant defence involving hydrogen peroxide and its univalent reduction product, the hydroxyl radical. Thyroid histopathology shows destruction of thyroid follicles and necrosis, which may be due to ROS and may partly explain the 50% reduction in circulating thyroid hormones seen after ricin administration.
authors.affiliation: Radiation Medicine Centre, Bhabha Atomic Research Centre, Tata Memorial Centre Annexe, Parel, Bombay, India.
authors.forename: G R
authors.initials: GR
authors.lastname: Sadani
authors.forename: C S
authors.initials: CS
authors.lastname: Soman
authors.forename: K K
authors.initials: KK
authors.lastname: Deodhar
authors.forename: G D
authors.initials: GD
authors.lastname: Nadkarni
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D005260:Female; D015227:Lipid Peroxidation; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012276:Ricin / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000378:metabolism; D013961:Thyroid Gland / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
chemical_list: D017382:Reactive Oxygen Species; D014284:Triiodothyronine; D012276:Ricin; D002374:Catalase; D013482:Superoxide Dismutase; D013974:Thyroxine