title: Effects of a single exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on macro- and microstructures of feeding and drinking in two differently TCDD-sensitive rat strains.
abstract: In rats, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes anorexia that may lead to fatal wasting but has hitherto been poorly characterized. Therefore, we studied in-depth feeding and drinking behaviors of TCDD-sensitive L-E rats for 5 (100 μg/kg; lethal dose) or 10 (10 μg/kg; sublethal) days and of TCDD-resistant H/W rats for 14 (100 or 1000 μg/kg; both sublethal) days postexposure to TCDD. The 1000-fold higher resistance of H/W rats to acute lethality of TCDD results from a mutation in their AH receptor (AHR). We split days into four (morning, daytime, evening, and night) or two (light/dark) circadian periods and took the repeated nature of the data into account. In L-E rats at 100 μg/kg, the feed intake dropped precipitously, due to reduced meal sizes. In H/W rats, the hypophagia remained moderate and stemmed from a reduced meal frequency. While the suppression in L-E rats peaked during the morning (at 100 μg/kg), the main effects in H/W rats were seen during the constant light or dark phases. Furthermore, chronologic data analysis revealed alterations in consecutive feeding and drinking patterns. Thus, striking differences were found between these strains in the timing and structure of consummatory behaviors, suggesting involvement of the AHR in these behaviors.
authors.affiliation: Department of Environmental Health, National Institute for Health and Welfare (THL), P.O.Box 95, FI-70701 Kuopio, Finland. sanna.t.k.lensu@jyu.fi
authors.forename: Sanna
authors.initials: S
authors.lastname: Lensu
authors.forename: Pekka
authors.initials: P
authors.lastname: Tiittanen
authors.forename: Jere
authors.initials: J
authors.lastname: Lindén
authors.forename: Jouko
authors.initials: J
authors.lastname: Tuomisto
authors.forename: Raimo
authors.initials: R
authors.lastname: Pohjanvirta
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects / Q000235:genetics; D004327:Drinking Behavior / Q000187:drug effects* / Q000502:physiology*; D004351:Drug Resistance / Q000235:genetics; D005247:Feeding Behavior / Q000187:drug effects* / Q000502:physiology*; D008297:Male; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity
chemical_list: D000072317:Polychlorinated Dibenzodioxins