title: Effect of temperature and duration of hyperthermia on HSP72 induction in rat tissues.
abstract: The aim of the present study was to determine whether heat shock protein 72 (HSP72) is induced in a heated rat model at rectal temperatures below 42 degrees C. Rats were divided into a control group and six groups (n = 6) heated to different rectal temperatures: 39 degrees C for 1 h (39), 40.0 degrees C for either 15 min (40S) or 1 h (40L), 41.0 degrees C for either 15 min (41S) or 1 h (41L) and 42.0 degrees C for 15 min (42). Tissues were sampled 4 h after heating. Following 1 h at 40.0 degrees C, HSP72 was significantly elevated in heart (p < 0.005), but not in gut or liver tissue. In all three tissues, HSP72 was significantly elevated under the conditions 41L and 42 compared to control tissue (p < 0.005). Marked differences were found in the amount of HSP72 induced in different tissues in response to the same heat stress. Duration of heating was important in modulating HSP72 induction, with a significantly greater induction of HSP72 following 1 h compared to 15 min at 41 degrees C in all three tissues (p < 0.02). A correlation was found between thermal load and HSP72 content in liver, heart (both p < 0.01) and gut (p < 0.001) for the rats heated to 41 and 42 degrees C. These data show that HSP72 is induced at temperatures below 42 degrees C, with striking differences between tissues.
authors.affiliation: School of Exercise and Sport Science, The University of Sydney, Sydney, NSW, Australia. P.Ruell@fhs.usyd.edu.au
authors.forename: P A
authors.initials: PA
authors.lastname: Ruell
authors.forename: K M
authors.initials: KM
authors.lastname: Hoffman
authors.forename: C M
authors.initials: CM
authors.lastname: Chow
authors.forename: M W
authors.initials: MW
authors.lastname: Thompson
mesh_terms: D000818:Animals; D001831:Body Temperature; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006358:Hot Temperature; D006979:Hyperthermia, Induced; D007421:Intestine, Small / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins