Immunotoxicity of bis(tri-n-butyltin) oxide in the rat.
Previous studies in the rat have shown that bis(tri-n-butyltin) oxide (TBTO), used as a biocide, was immunotoxic at dose levels that did not affect other organs. In order to determine a no-effect level, weanling rats were treated for at least 28 consecutive days with TBTO at 0, 0.5, 2, 5, or 50 mg/kg of diet. Studies on clinical chemistry, hematology, pathology, and immune function, that is, plaque-forming cell (PFC) assay, delayed-type hypersensitivity (DTH) response, and the splenic clearance of Listeria monocytogenes, were performed at the end of treatment. No treatment-related effects were noted on clinical chemistry and hematology parameters and on PFC and DTH response, whereas thymic atrophy and impaired clearance of L. monocytogenes were noted only at a dietary concentration of 50 mg/kg. These results confirm the thymus as a target organ of TBTO immunotoxicity. Under the conditions of these experiments the dietary concentration of 5 mg/kg, equivalent to a dose of 0.5 mg/kg body weight, represents a no observed effect level (NOEL) for immunotoxicity in the Sprague-Dawley rat.
Verdier
F
F
Laboratoire d'Immunotoxicologie Fondamentale et Clinique, Faculté de Médecine A. Carrel, Lyon, France.
Virat
M
M
Schweinfurth
H
H
Descotes
J
J
D000284:Administration, Oral; D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D006462:Hemolytic Plaque Technique; D006968:Hypersensitivity, Delayed; D007166:Immunosuppressive Agents / Q000276:immunology / Q000633:toxicity*; D008089:Listeria monocytogenes / Q000187:drug effects / Q000276:immunology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013950:Thymus Gland / Q000187:drug effects; D014220:Trialkyltin Compounds / Q000276:immunology / Q000633:toxicity*
D007166:Immunosuppressive Agents; D014220:Trialkyltin Compounds; C005961:bis(tri-n-butyltin)oxide