HSP72 gene expression progressively increases in human skeletal muscle during prolonged, exhaustive exercise

J Appl Physiol (1985). 2000 Sep;89(3):1055-60. doi: 10.1152/jappl.2000.89.3.1055.

Abstract

To examine the effect of exercise on heat shock protein (HSP) 72 mRNA expression in skeletal muscle, five healthy humans (20 +/- 1 yr; 64 +/- 3 kg; peak O(2) uptake of 2.55 +/- 0.2 l/min) cycled until exhaustion at a workload corresponding to 63% peak O(2) uptake. Muscle was sampled from the vastus lateralis, and muscle temperature was measured at rest (R), 10 min of exercise (Min10), approximately 40 min before fatigue (F-40 = 144 +/- 7 min), and fatigue (F = 186 +/- 15 min). Muscle samples were analyzed for HSP72 mRNA expression, as well as glycogen and lactate concentration. Muscle temperature increased (P < 0.05) during the first 10 min of exercise but then remained constant for the duration of the exercise. Similarly, lactate concentration increased (P < 0.05) when Min10 was compared with R but decreased (P < 0.05) thereafter, such that concentrations at F-40 and F were not different from those at R. In contrast, muscle glycogen concentration fell progressively throughout exercise (486 +/- 74 vs. 25 +/- 7 mmol/kg dry weight for R and F, respectively; P < 0.05). HSP72 mRNA was detected at R but did not increase by Min10. However, HSP72 mRNA increased (P < 0.05) 2.2 +/- 0.5- and 2.6 +/- 0.9-fold, respectively, when F-40 and F were compared with R. These data demonstrate that HSP72 mRNA increases progressively during acute cycling, suggesting that processes that take place throughout concentric exercise are capable of initiating a stress response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bicycling
  • Exercise / physiology*
  • Gene Expression / physiology*
  • Glycogen / metabolism
  • HSP72 Heat-Shock Proteins
  • Heat-Shock Proteins / genetics*
  • Homeostasis
  • Humans
  • Lactic Acid / metabolism
  • Muscle, Skeletal / physiology*
  • Physical Endurance*
  • RNA, Messenger / metabolism
  • Time Factors

Substances

  • HSP72 Heat-Shock Proteins
  • Heat-Shock Proteins
  • RNA, Messenger
  • Lactic Acid
  • Glycogen