title: Immunological responses to chronic heat exposure and food restriction in rats.
abstract: Immunological variables were studied in rats chronically exposed to high environmental temperature (35 degrees C). Responses were compared with those of rats at 25 degrees C both fed ad libitum and pair fed to the decreased intake found in heat-exposed rats. Heat-exposed rats showed slower delayed-type hypersensitivity responses to keyhole limpet hemocyanin. They showed lower counts of peripheral blood total T cells (OX19+) as well as helper T cells (W3/25+) and smaller numbers of splenic T cells. The thymus was decreased in size. Increased levels of serum IgG antitetanus toxoid antibodies were found in heat-exposed rats. [3H]-thymidine incorporation into Concanavalin A (ConA)-stimulated splenic lymphocytes was decreased in pair-fed rats but not significantly altered in heat-exposed rats compared with controls. Heat exposure alters some aspects of both cellular and humoral immune function in a manner different from that induced by comparable food restriction without heat exposure.
authors.affiliation: Department of Surgery, Royal Victoria Hospital, Montreal, Quebec, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Chayoth
authors.forename: N V
authors.initials: NV
authors.lastname: Christou
authors.forename: C W
authors.initials: CW
authors.lastname: Nohr
authors.forename: J F
authors.initials: JF
authors.lastname: Yale
authors.forename: P
authors.initials: P
authors.lastname: Poussier
authors.forename: M
authors.initials: M
authors.lastname: Grose
authors.forename: M
authors.initials: M
authors.lastname: Montambault
authors.forename: W
authors.initials: W
authors.lastname: Chan
authors.forename: E B
authors.initials: EB
authors.lastname: Marliss
mesh_terms: D000818:Animals; D000917:Antibody Formation; D003208:Concanavalin A / Q000494:pharmacology; D005508:Food Deprivation; D006358:Hot Temperature; D006968:Hypersensitivity, Delayed; D007958:Leukocyte Count; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013745:Tetanus Toxoid / Q000276:immunology
chemical_list: D013745:Tetanus Toxoid; D003208:Concanavalin A