title: Role of calcitonin gene-related peptide in cardioprotection of short-term and long-term exercise preconditioning.
abstract: OBJECTIVE
  To examine the role of calcitonin gene-related peptide (CGRP) in cardioprotection of short-term and long-term exercise preconditioning (EP).
  
  
  METHODS
  Male Sprague-Dawley rats were, respectively, subjected to continuous intermittent treadmill training 3 days or 3 weeks as short-term or long-term EP protocols. The myocardial injury induced by isoproterenol (ISO) was performed 24 hours after short-term and long-term EP. The myocardial injury was evaluated in terms of the serum cardiac troponin levels and the hematoxylin-basic fuchsin-picric acid staining. Additionally, serum CGRP levels, CGRP expression in the dorsal root ganglion (DRG), and heart were analyzed as possible mechanisms to explain short-term and long-term EP-induced cardioprotection.
  
  
  RESULTS
  Both short-term and long-term EP markedly attenuated the isoproterenol-induced myocardial ischemia with lower serum cardiac troponin levels. Short-term EP does not alter serum CGRP levels and CGRP expression in the DRG and heart. Long-term EP significantly increases serum CGRP levels and CGRP expression in the DRG and heart.
  
  
  CONCLUSIONS
  The results indicate that short-term EP does not increase the synthesis and release of CGRP. Therefore, the cardioprotective effect of short-term EP does not involve CGRP adaptation. Furthermore, long-term EP increases CGRP synthesis in the DRG and promotes CGRP release in the blood and heart. Hence, CGRP may play an important role in the cardioprotective effect of long-term EP.
authors.affiliation: *Department of Physical Education, Xianyang Normal University, Xianyang, China; and †Department of Sports Anatomy, School of Sports Science, Shanghai University of Sport, Shanghai, China.
authors.forename: Xiao-Juan
authors.initials: XJ
authors.lastname: Sun
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Pan
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods*; D007545:Isoproterenol / Q000633:toxicity; D008297:Male; D017202:Myocardial Ischemia / Q000517:prevention & control*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014336:Troponin / Q000097:blood
chemical_list: D014336:Troponin; D015740:Calcitonin Gene-Related Peptide; D007545:Isoproterenol