title: [Influence of exercise on both et levels in plasma and myocardial cells and ET receptor on the myocardial cells membrane in rats].
abstract: OBJECTIVE
  The purpose of the present study is to discuss the influence of different exercise load on the concentration of ET in plasma and myocardial cells, and the activity of ETR on myocardial cell's membrane in rats.
  
  
  METHODS
  45 male SD rats were divided into the following 5 groups randomly: Group A (control group); Group B (45 min swim group); Group C (90 min swim group); Group D (150 min swim group); Group E (acute exhaust group). After having been trained for 8 weeks, the levels of ET and activity of ETR were measured by RIA.
  
  
  RESULTS
  The concentrations of ET in plasma and myocardial cells of 90 min swim group were decreased significantly (P < 0.01)and 90 min swim could reduce the activity of ETR (P < 0.01). The activity of ETR was elevated significantly in 150 min swim group (P < 0.01).
  
  
  CONCLUSIONS
  Moderate exercise loads can significantly ameliorate the cardiovascular function, and high exercise loads is harmful to myocardial cells.
authors.affiliation: School of Physical Education, East China JiaoTong University, Nanchang 330013, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Sun
mesh_terms: D000818:Animals; D019332:Endothelin-1 / Q000378:metabolism*; D008297:Male; D032383:Myocytes, Cardiac / Q000378:metabolism*; D010805:Physical Conditioning, Animal / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D044022:Receptor, Endothelin A / Q000378:metabolism*; D013550:Swimming
chemical_list: D019332:Endothelin-1; D044022:Receptor, Endothelin A