title: Effects of α-methylnorepinephrine on cardiac function and myocardium at early stage of resuscitation in rabbits.
abstract: BACKGROUND
  Recent studies have shown that α2-adrenergic agonists can reduce postresuscitation myocardial injury. This study was undertaken to observe changes of hemodynamics, myocardial injury markers cTnT and cardiac morphology by establishing a cardiopulmonary resuscitation model with rabbits, and to detect whether α-methyl norepinephrine (α-MNE) can reduce the myocardial injury after CPR and improve cardiac function.
  
  
  METHODS
  Eighteen health rabbits, weighing 2.5-3.5 kg, both male and female, were provided by the Lanzhou Institute of Veterinary Medicine. After setting up a rabbit model of cardiopulmonary resuscitation, 18 rabbits were randomly divided into three groups. The rabbits in group A as an operation-control group were subjected to anesthesia, endotracheal intubation, and surgery without induction of ventricular fibrillation. The rabbits in group B as an epinephrine group were administered with 30 μg/kg epinephrineduring CPR. The rabbits in group C as a MNE group were administered with 100 μg/kg a-MNE during CPR. The left ventricular end-diastolic pressure (LVEDP), left ventricular pressure rise and fall rate (±dp/dt) and serum concentrations of BNP were measured. Statistical package of SPSS 10.0 was used for data analysis and significant differences between means were evaluated by ANOVA.
  
  
  RESULTS
  Compared to group A, the LVEDP of other two groups increased respectively (P<0.01 all), and peak±dp/dt decreased in the other two groups (P<0.01). The increase of LVEDP was lower in group C than in group B (P<0.05), whereas peak±dp/dt was higher in group C than in group B (P<0.05) at the same stage. Compared to group A, the cTnT of the remaining two groups increased, respectively (P<0.01), and peaked at 30 minutes. cTnT was less elevated in group C than in group B (P<0.05) during the same period. In groups B and C, myocardial injury was seen under a light microscope, but the injury in group C was lighter than that in group B.
  
  
  CONCLUSIONS
  Methylnorepinephrine can lessen myocardial dysfunction after CPR.
authors.affiliation: Department of Anesthesia Medicine, the Second Hospital of Lanzhou University, Lanzhou 730030, China.
authors.forename: Pei-Jie
authors.initials: PJ
authors.lastname: Li
authors.affiliation: Department of Anesthesia Medicine, the Second Hospital of Lanzhou University, Lanzhou 730030, China.
authors.forename: Xiao-Hua
authors.initials: XH
authors.lastname: Yang
authors.affiliation: Department of Anesthesia Medicine, the Second Hospital of Lanzhou University, Lanzhou 730030, China.
authors.forename: Zheng-Yi
authors.initials: ZY
authors.lastname: Zhang
authors.affiliation: Department of Anesthesia Medicine, the Second Hospital of Lanzhou University, Lanzhou 730030, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Cao
authors.affiliation: Department of Anesthesia Medicine, the Second Hospital of Lanzhou University, Lanzhou 730030, China.
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Zhang
authors.affiliation: Department of Anesthesia Medicine, the Second Hospital of Lanzhou University, Lanzhou 730030, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Qin
authors.affiliation: Department of Anesthesia Medicine, the Second Hospital of Lanzhou University, Lanzhou 730030, China.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Wang
keywords: Cardiopulmonary resuscitation;; Post-resuscitation myocardial dysfunction; α2-adrenergic agonist;