Changes of HSP72-expression in leukocytes are associated with adaptation to exercise under conditions of high environmental temperature

  1. Hinnak Northoff*
  1. *Department of Transfusion Medicine, and
  2. Medical Clinic and Polyclinic, Department of Sports Medicine, University of Tuebingen, Tuebingen, Germany
  1. Correspondence: Elvira Fehrenbach, Ph.D., Abteilung Transfusionsmedizin, Eberhard-Karls-Universitaet Tuebingen, Otfried-Mueller-Str. 4/1, D-72076 Tuebingen, Germany. E-mail:elvira.fehrenbach{at}med.uni-tuebingen.de

Abstract

Overexpression of the heat shock protein HSP72 providesthermotolerance. We asked if two consecutive endurance runs 1 weekapart (CR1, CR2) and additional environmental heat stress affectHSP72-expression in leukocytes of nonheat-acclimated enduranceathletes. Twelve subjects were allocated randomly into two groups.Group HH completed both runs at 28°C ambient temperature, and groupNH performed CR1 at 18°C and CR2 at 28°C. HSP72-expression wasdetermined by flow cytometry and RT-PCR before and 0, 24, and 48 hafter exercise. Additionally, post-exercise cells were exposed toin vitro heat shock (HS; 2 h, 42°C). The prolonged,high HSP72 protein level after CR1 in HH compared with NH may reflectthermotolerance induced by endurance exercise at high ambienttemperature. Adaptation of cardiocirculatory/thermoregulatory capacityafter CR2 in HH went along with a more rapid down-regulation of HSP72compared with CR1. HSP72 mRNA demonstrated temperature-related changesafter exercise. The reduced HS response in vitro after CR2may represent exercise-related adaptation mechanisms. HSP72concentrations in leukocytes may indicate previous exercise- andtemperature-related stress conditions and adaptation in immunocompetentcells.

  • Received March 30, 2000.
  • Revision received October 11, 2000.
  • Accepted January 5, 2001.
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