title: Histopathological effects of chronic aqueous exposure to bis(tri-n-butyltin)oxide (TBTO) to environmentally relevant concentrations reveal thymus atrophy in European flounder (Platichthys flesus).
abstract: Although the use of tributyltin in antifouling paints has been banned, this compound is still a serious pollutant of the marine environment. This paper describes a unique study in which European flounder (Platichthys flesus) were chronically (8 months) exposed to bis(tri-n-butyltin)oxide (TBTO) in the water under controlled laboratory conditions. Residue levels in selected tissues (liver, muscle) and general health status indices were measured and the effects on several organs (gills, liver, mesonephros, ovary/testis, spleen, and gastrointestinal tract) were examined histopathologically. Additionally, morphometric analysis of the thymus was performed. The major finding is that exposure of flounder to 5 microg TBTO/l over a period of 8 months, resulting in body burdens comparable to high field levels, induced significant reduction of thymus volume, possibly affecting immunocompetence of the animals. Chronic exposure of European flounder to tributyltin is therefore likely to affect the general health status of this species in heavily polluted aquatic environments.
authors.affiliation: Department of Pathobiology, Faculty of Veterinary Medicine University of Utrecht, P.O. Box 80.158, 3508 TD Utrecht, The Netherlands. g.c.m.grinwis@uu.nl
authors.forename: G C M
authors.initials: GC
authors.lastname: Grinwis
authors.forename: P W
authors.initials: PW
authors.lastname: Wester
authors.forename: A D
authors.initials: AD
authors.lastname: Vethaak
mesh_terms: D000825:Animal Structures / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D000818:Animals; D004781:Environmental Exposure; D005393:Fish Diseases / Q000378:metabolism / Q000473:pathology*; D005432:Flounder / Q000254:growth & development / Q000378:metabolism; D008206:Lymphatic Diseases / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D013950:Thymus Gland / Q000737:chemistry / Q000473:pathology*; D014220:Trialkyltin Compounds / Q000378:metabolism / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014220:Trialkyltin Compounds; D014874:Water Pollutants, Chemical; C005961:bis(tri-n-butyltin)oxide