Int J Sports Med 2008; 29(4): 269-276
DOI: 10.1055/s-2007-965331
Physiology & Biochemistry

© Georg Thieme Verlag KG Stuttgart · New York

Heat Acclimation and HSP-72 Expression in Exercising Humans

A. M. Watkins1 , D. J. Cheek2 , A. E. Harvey1 , K. E. Blair1 , J. B. Mitchell1
  • 1Department of Kinesiology, TCU, Fort Worth, TX, United States
  • 2Harris School of Nursing, TCU, Fort Worth, TX, United States
Further Information

Publication History

accepted after revision March 15, 2007

Publication Date:
18 September 2007 (online)

Abstract

The purpose of this research was to determine the effect of a 7-day heat acclimation protocol on HSP-72 expression in human skeletal muscle, and to examine the relationships between molecular and physiological markers of heat acclimation. Ten recreationally active male subjects (age = 23.3 ± 2.81 yrs, V·O2peak = 3.85 ± 0.11 L · min-1) completed a 7-day heat acclimation protocol consisting of cycling at 75 % of V·O2peak in a hot environment (39.5 °C, 27 % RH). Muscle biopsies were obtained on days 1 (HTT1) and 7 (HTT2) prior to, 6 h post, and 24 h postexercise to measure HSP-72 protein via SDS-PAGE and silver staining. Core rectal temperatures (TC), intramuscular temperatures (TIM), skin temperatures (TSK), heart rate (HR), oxygen uptake (V·O2), sweat rate (SR), and plasma cortisol were measured. TC, HR, and plasma cortisol were significantly lower in HTT2 than HTT1 (p ≤ 0.05). No significant differences were seen for V·O2, TIM, TSK, or SR when comparing HTT2 with HTT1 (p ≤ 0.05). No significant time or day × time interactions were detected for HSP-72 expression (24.48 ± 2.55 vs. 25.04 ± 1.43 ng/µg protein for HTT1 and HTT2, respectively, p ≤ 0.05). Evidence of heat acclimation was seen at the physiological level; however, no evidence of enhanced thermotolerance at the cellular level was indicated by HSP-72 expression.

References

Dr. J. B. Mitchell

Department of Kinesiology
TCU

P. O. Box 297730

Fort Worth, TX 76129

United States

Phone: + 1 81 72 57 76 65

Fax: + 1 81 72 57 77 02

Email: j.mitchell@tcu.edu