Linked Life Data

9520139

Source:http://linkedlifedata.com/resource/pubmed/id/9520139

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-5-14
pubmed:abstractText
Previous studies have demonstrated that repeated (14 day) administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) enhances the suppression of humoral immunity in DBA/2 (Ah-low responder) mice relative to the effect seen with identical cumulative doses after a single treatment (cumulative doses of 4.2, 14.0, and 42 mg/kg). In the present studies, we have explored this phenomenon further by determining the status of several specific parameters, which might account for the increase in antibody suppression in the DBA/2 strain following repeated TCDD exposures. Included in these studies was the induction of hepatic and splenic microsomal 7-ethoxyresorufin-o-deethylase (EROD; P4501A1) activity and biodistribution of the administered TCDD into various target organs and tissues. Changes in lymphocyte subpopulations within the spleen were also assessed by flow cytometry following both single and repeated dosing. All studies made use of direct comparisons between DBA/2 (Ah-low responder) and B6C3F1 (Ah-high responder) female mice. Results of these studies demonstrate that the enhanced suppression of humoral immunity in DBA/2 mice following repeated exposure to TCDD is not directly associated with increases in liver microsomal EROD activity and does not appear to be correlated with changes in the pattern of biodistribution or amount of TCDD within the liver or spleen of these animals. In contrast, the most significant changes that occurred following repeated dosing in either strain were observed in the levels of microsomal EROD activity and immune cell ratios within the spleen. This effect was characterized as an increase in microsomal EROD activity, and a corresponding reduction in the numbers of a non-B/non-T cell population in the spleen.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0340-5761
pubmed:author
pubmed:issnType
Print
pubmed:volume
72
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
157-68
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Characterization of the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin in B6C3F1 and DBA/2 mice following single and repeated exposures.
pubmed:affiliation
Department of Pharmacology and Toxicology, Medical College of Virginia/Virginia Commonwealth University, Richmond 23298, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't