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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1998-9-16
pubmed:abstractText
Recent studies have shown that perinatal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) alters thermoregulatory function in adult rats and hamsters, indicated by a reduced body temperature during the animal's nocturnal phase. The present study was designed to assess the behavioral thermoregulation, ability to develop a fever, and thermoregulatory stability as a function of ambient temperature (Ta) in rats exposed perinatally to TCDD. Pregnant Long-Evans rats were exposed on gestational day (GD) 15 to 1 microg TCDD/kg (po). The male offspring were implanted with transmitters to monitor core temperature (Tc) and motor activity (MA). The 24-h pattern of core temperature was affected by TCDD exposure, characterized by a reduced nocturnal Tc. At some ages, the diurnal Tc of the TCDD group was elevated. This dysfunction in temperature regulation was most apparent at 7 and 11 mo of age. The 24-h pattern of MA was also altered by TCDD. The hypothermic effects of TCDD were most pronounced at cooler Ta values of 10 to 22 degrees C. In contrast, behavioral thermoregulation, assessed by measuring the selected Ta and Tc of rats in a temperature gradient, was unaffected by TCDD. The ability to develop a fever following administration of lipopolysaccharide (LPS) endotoxin (Escherichia coli; 50 microg/kg) was accentuated in the TCDD-treated animals. The data confirm a nocturnal hypothermia in rats prenatally exposed to TCDD. However, the normal behavioral regulation of Tc suggests that hypothalamic thermoregulatory centers are not permanently altered. The accentuated fever in TCDD animals shows possible functional alterations in the neuroimmune and/or thermoregulatory axes involved in fever.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1528-7394
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
54
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
647-62
pubmed:dateRevised
2006-2-16
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Thermoregulation in rats exposed perinatally to dioxin: core temperature stability to altered ambient temperature, behavioral thermoregulation, and febrile response to lipopolysaccharide.
pubmed:affiliation
Neurotoxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA. gordon@herl45.herl.epa.gov
pubmed:publicationType
Journal Article