title: Effects of heat preconditioning on overload training induced myocardial injury.
abstract: OBJECTIVE
  The present study was to investigate the protective effects and mechanisms of heat preconditioning (HP) on myocardial injury induced by the overload training.
  
  
  METHODS
  A total of 25 male Sprague-Dauley (SD) rats were randomly divided into three groups: control group, training group and HP group. The activities of creatine kinase (CK), catalase (CAT) and superoxide dismutase (SOD) of myocardium, apoptosis index (AI), expressions of Bcl-2, Bax, caspase-3, caspase-9, ICAM-1, VCAM-1, and PECAM-1 were determined after 8-week overload training.
  
  
  RESULTS
  Results showed the CK activity, myocardial apoptosis rate and AI in training group were significantly higher than control group and HP group (P<0.05), while the activities of CAT and SOD of training group and HP group were slightly lower than control group (P>0.05). The Bcl-2 expression in HP group was significantly higher than control group and training group, while the ratio of Bcl-2/Bax of training group was significantly lower than control group and HP group. The expressions of caspase-3, caspase-9, ICAM-1, VCAM-1 and PECAM-1 in training group and HP group were significantly higher than control group. Significant differences in the expressions of caspase-3, and caspase-9 was also noted between training group and HP group, but there was no marked difference in the expressions of ICAM-1, VCAM-1 and PECAM-1 between these two groups.
  
  
  CONCLUSIONS
  HP could adjust the activities of CK, CAT and SOD, regulate the expressions of apoptosis-related genes and adhesion molecules resulting in enhanced capacity against overload training induced injury and reduced damage to the myocardium.
authors.affiliation: College of Health Science, Wuhan Institute of Physical Education, Wuhan, China. yangyi999999@yahoo.com
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.forename: Z
authors.initials: Z
authors.lastname: Li
authors.forename: H
authors.initials: H
authors.lastname: Liu
authors.forename: W
authors.initials: W
authors.lastname: Shi
authors.forename: J
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000818:Animals; D017209:Apoptosis; D002374:Catalase / Q000378:metabolism; D003402:Creatine Kinase / Q000378:metabolism; D006979:Hyperthermia, Induced; D008297:Male; D009206:Myocardium / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000473:pathology; D010805:Physical Conditioning, Animal; D005082:Physical Exertion / Q000502:physiology*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D002374:Catalase; D013482:Superoxide Dismutase; D003402:Creatine Kinase