title: [The change of adrenergic receptor-adenyl cyclase system on myocardial ischemic preconditioning in rats].
abstract: OBJECTIVE
  To study the varies and effects of ischemic preconditioning of myocardium on every part of adrenergic receptor-adenyl cyclase system in rats in vivo.
  
  
  METHODS
  SD rats were randomly divided into three groups: CON group (n = 6), IP group (n = 12) and I/R group (n = 12). Surgical procedure included intermittent left coronary artery occlusion and reperfusion. After the procedure, the hearts were extracted. We analyzed the infarct size by TTC staining, measured serum myocardial enzymes, studied the beta-AR Bmax and KD by radioligand binding assay of receptors (RAB), and checked the activity of AC and the content of cAMP by radioimmunoassay (RIA).
  
  
  RESULTS
  Infarct area were much smaller in IP group than in I/R group (P < 0.05). CK, CK-MB, LDH were significantly higher in I/R group (P < 0.01). The Bmax of beta-AR in IP group were much higher than in I/R group (P < 0.01). No difference of KD could be seen between IP and I/R group. In IP group, the activity of AC and the content of cAMP were higher than I/R group (P < 0.05).
  
  
  CONCLUSIONS
  Ischemic preconditioning can protect the heart from necrosis and reduce endo-enzyme leakage. Ischemic preconditioning can increase the density of beta-AR, the activity of AC and the content of cAMP, which shows that the system of adrenergic receptor-adenyl cyclase system probably takes part in the protection of IP.
authors.affiliation: Department of Nuclear Medicine, The Second Hospital, China Medical University, Shenyang 110004, China.
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Lan
authors.forename: Shu-Xia
authors.initials: SX
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Zhu-Guo
authors.initials: ZG
authors.lastname: Pei
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D005260:Female; D019157:Ischemic Preconditioning, Myocardial; D017202:Myocardial Ischemia / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*
chemical_list: D011943:Receptors, Adrenergic, beta; D000262:Adenylyl Cyclases