The cortical epithelium of the rat thymus after in vivo exposure to bis(tri-n-butyltin)oxide (TBTO). An (immuno)histological and ultrastructural study.
Bis(tri-n-butyltin)oxide (TBTO) induces cortical atrophy in the rat thymus. We studied the potential involvement of the cortical epithelium in TBTO-induced thymotoxicity by (immuno) histology and electron microscopy. Juvenile male Wistar rats were orally intubated once with either 30 or 90 mg/kg TBTO and sacrificed 4 or 10 days later. A dose-dependent thymic atrophy occurred. Anti-keratin labelling showed epithelial cell aggregation in some animals at 10 days after exposure to 90 mg/kg TBTO, when recovery of the thymus was apparent. At the ultrastructural level, a relative shift was observed from "pale" to darker epithelial cell subtypes at the 30 mg/kg dose level, both at day 4 and day 10 after intubation. This phenomenon was not observed after exposure to 90 mg/kg TBTO. Both the altered keratin distribution and the increased electron density of the epithelium probably represent non-specific phenomena. The present morphological observations support the concept that TBTO affects the thymus via its action on lymphoid cells rather than on the epithelial compartment.
National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
E J
EJ
De Waal
H J
HJ
Schuurman
L H
LH
Rademakers
H
H
Van Loveren
J G
JG
Vos
D000818:Animals; D004848:Epithelium / Q000187:drug effects / Q000473:pathology / Q000648:ultrastructure; D007150:Immunohistochemistry; D007166:Immunosuppressive Agents / Q000494:pharmacology* / Q000633:toxicity; D008297:Male; D008854:Microscopy, Electron; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013950:Thymus Gland / Q000187:drug effects* / Q000473:pathology / Q000648:ultrastructure; D014220:Trialkyltin Compounds / Q000494:pharmacology* / Q000633:toxicity
D007166:Immunosuppressive Agents; D014220:Trialkyltin Compounds; C005961:bis(tri-n-butyltin)oxide