title: Leukocyte Hsp72 mRNA transcription does not differ between males and females during heat acclimation.
abstract: Purpose:Thermotolerance is an acquired state of increased cytoprotection achieved following single or repeated exposures to heat stress, in part characterized by changes in the intracellular 72 kda heat shock protein (HSP72; HSPA1A). Females have demonstrated reduced exercise induced HSP72 in comparison to males. This study examined sex differences in heat shock protein 72 messenger ribonucleic acid (Hsp72 mRNA) transcription during heat acclimation (HA) to identify whether sex differences were a result of differential gene transcription.Methods:Ten participants (5M, 5F) performed 10, 90 min controlled hyperthermia [rectal temperature (Tre) ≥ 38.5°C] HA sessions over 12 d. Leukocyte Hsp72 mRNA was measured pre and post D1, D5, and D10, via Reverse transcription polymerase chain reaction (RT-QPCR).Results:HA was evidenced by a reduction in resting Tre(-0.4 ± 0.5°C) and resting heart rate [(HR); -13 ± 7 beats.min-1] following HA (p ≤ 0.05). During HA no difference (p> 0.05) was observed in ΔTrebetween males (D1 = 1.5 ± 0.2°C; D5 = 1.6 ± 0.4°C; D10 = 1.8 ± 0.3°C) and females (D1 = 1.5 ± 0.5°C; D5 = 1.4 ± 0.2°C; D10 = 1.8 ± 0.3°C). This was also true of mean Tredemonstrating equality of thermal stimuli for mRNA transcription and HA. There were no differences (p> 0.05) in Hsp72 mRNA expression between HA sessions or between males (D1 = +1.8 ± 1.5-fold; D5 = +2.0 ± 1.0 fold; D10 = +1.1 ± 0.4-fold) and females (D1 = +2.6 ± 1.8-fold; D5 = +1.8 ± 1.4-fold; D10 = +0.9 ± 1.9-fold).Conclusions:This experiment demonstrates that there is no difference in Hsp72 mRNA increases during HA between sexes when controlled hyperthermia HA is utilised. Gender specific differences in exercise-induced HSP72 reported elsewhere likely result from post-transcriptional events.
authors.affiliation: Centre for Sport and Exercise Science and medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin Human Performance Laboratories, Denton Road, Eastbourne, UK; School of Sport, Health, and Exercise Science, Bangor University, Bangor, UK.
authors.forename: J A
authors.initials: JA
authors.lastname: Mee
authors.affiliation: Centre for Sport and Exercise Science and medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin Human Performance Laboratories, Denton Road, Eastbourne, UK; Centre for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University, London, UK.
authors.forename: O R
authors.initials: OR
authors.lastname: Gibson
authors.affiliation: Muscle Cellular and Molecular Physiology (MCMP) and Applied Sport and Exercise Science (ASEP) Research Groups, Institute of Sport and Physical Activity Research (ISPAR), University of Bedfordshire , Bedford, UK.
authors.forename: J A
authors.initials: JA
authors.lastname: Tuttle
authors.affiliation: ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital, Athlete Health and Performance Research Centre, Aspire Zone, Doha, Qatar; School of Sport, Exercise and Health Sciences. Loughborough University, Loughborough, UK.
authors.forename: L
authors.initials: L
authors.lastname: Taylor
authors.affiliation: Centre for Sport and Exercise Science and medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin Human Performance Laboratories , Denton Road , Eastbourne, UK.
authors.forename: P W
authors.initials: PW
authors.lastname: Watt
authors.affiliation: Centre for Sport and Exercise Science and medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin Human Performance Laboratories , Denton Road , Eastbourne, UK.
authors.forename: J
authors.initials: J
authors.lastname: Doust
authors.affiliation: Centre for Sport and Exercise Science and medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin Human Performance Laboratories , Denton Road , Eastbourne, UK.
authors.forename: N S
authors.initials: NS
authors.lastname: Maxwell
keywords: controlled hyperthermia; females; heat shock protein; males; thermotolerance