title: Inverse response of leukocyte heat shock proteins and DNA damage to exercise and heat.
abstract: Elevated ambient temperature may exert an additional impact on the exercise-induced expression of heat shock proteins (HSP) and DNA damage in leukocytes. The protective functions of HSP include antioxidative and antiapoptotic effects and may prevent damage to DNA. Twelve athletes completed a continuous run (75% VO2max) on the treadmill, six at 28 degrees C and six at 18 degrees C room temperature. Leukocyte expression of HSP27 and inducible HSP70 was analyzed on mRNA- (RT-PCR) and protein-level (flow cytometry), while DNA damage was quantified by the comet assay. High ambient temperature induced an additional accumulation of HSP-mRNA and -protein in leukocytes compared with the exercise-induced expression at 18 degrees C. HSP27 showed a special heat sensitivity. Surprisingly, the increase of DNA damage was less pronounced after exercise at 28 degrees C compared to 18 degrees C although heat shock in vitro clearly induced DNA damage. The inverse relation between HSP and DNA damage may indicate functions of HSP which protect against exercise-induced DNA-damage in terms of thermotolerance or apoptosis.
authors.affiliation: Department of Transfusion Medicine, University of Tuebingen, Otfried-Mueller-Street 4/1, D-72076 Tuebingen, Germany. elvira.fehrenbach@med.uni-tuebingen.de
authors.forename: Elvira
authors.initials: E
authors.lastname: Fehrenbach
authors.forename: Roman
authors.initials: R
authors.lastname: Veith
authors.forename: Mathias
authors.initials: M
authors.lastname: Schmid
authors.forename: Hans-Herrmann
authors.initials: HH
authors.lastname: Dickhuth
authors.forename: Hinnak
authors.initials: H
authors.lastname: Northoff
authors.forename: Andreas Michael
authors.initials: AM
authors.lastname: Niess
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D017209:Apoptosis / Q000502:physiology*; D020552:Comet Assay; D004249:DNA Damage; D017931:DNA Primers; D005434:Flow Cytometry; D015870:Gene Expression; D006339:Heart Rate; D006360:Heat-Shock Proteins / Q000502:physiology*; D006358:Hot Temperature; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D010101:Oxygen Consumption; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012420:Running
chemical_list: D017931:DNA Primers; D006360:Heat-Shock Proteins; D012333:RNA, Messenger