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 g/kg epinephrineduring CPR. The rabbits in group C as a MNE group were administered with 100 g/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. CONCLUSION:Methylnorepinephrine can lessen myocardial dysfunction after CPR.
ABSTRACT
Objective To observe the effects of selective α2-adrenergic receptor agonist alpha-Methylnore-pinephrine(α-MNE) as a vasopressin agent on hemodynamics, troponin T(cTnT) and myocardium in the rabbit cardiopulmonary resuscitation. Method Eighteen health rabbits, weighing 2.5 - 3.5 kg, both male and female,were provided by Lanzhou institute of veterinary medicine. After setting up rabbit model of cardiopulmonary resuscitation, 18 rabbits were randomly divided into three groups. The rabbits in group A as a operation-control group were processed with anesthesia, endotracheal intubation, and surgery without ventricular fibrillation induced. The rabbits in group B as a epinephrine group were administered with 30 ug/kg epinephrineduring CPR. The rabbits in group C as a MNE group were administered with 100 ug/kg α-MNE during CPR. The left ventrictdar end-diastolic pressure(LVEDP), left ventricular pressure rise and fall rate(± dp/dt) and serum concentrations of BNP were measured. Statistic package of SPSS 10.0 was used for the data analysis and significant differences between means were evaluated by ANOVA analysis. Results Compared with group A, LVEDP of other two groups gradually increased respectively(P < 0. 01), and peak ± dp/dt decreased in other two groups(P<0.01). Increase in LVEDP in group C was less than that in group B(P<0.05), whereas peak ± dp/dt in group C were higher than that in group B(P<0.05), at the same stage. Compared with group A, the cTnT of the remaining two groups increased(P<0.01, respectively),and reached peak at 30 minutes. In group C, the elevation of cTnT was less than that in group B(P<0.05) during the same period. In group B and C, myocardial injury was seen under a light microscope, but the injury in group C was lighter than that in group B. Conclusion The methylnorepinephrine can lessen the myocardial dysfunction after CPR.