RESUMO
ObjectiveTo investigate the effect of β-adrenoceptor (β-AR) blockers on G protein and heart function changes in rats with acute myocardial infarction (AMI) MethodsWistar rats with AMI induced by left anterior descending coronary branch ligation were randomly divided into compared with sham operation group. Eight weeks after therapy, hemodynamics was assessed by inserting catheters and the level of G protein was detected by Western blot analysis. ResultsCompared with the sham operation group, systolic blood pressure(SBP), diastolic blood pressure (DBP), left ventricular systolic pressure(LVSP) and left ventrieular pressure maximal rate of rise and fall(±dp/dtmax) in AMI group were significantly decreased, while left ventricular end diastolic pressure (LVEDP) and Gs and Gi protein levels were significantly increased (all P<0.05). Compared with AMI group, LVSP and ± dp/dtmax were increased, but LVEDP and Gi protein level were significantly decreased in metoprolol and carvedilol group. LVEDP and Gi protein level were decreased in carvedilol group compared with metoprolol group. ConclusionsCarvedilol can effectively suppress the change of G protein and improve the heart function after AMI, and the effect is better than that of metoprolol. This may be related with its β2-AR blocking effect.
RESUMO
Objective To study the therapeutic effects of Enalapril on hemodynamic indexes in cardiac shock dogs induced by acute right ventricular myocardial infarction(RVMI).Methods Models of RVMI accompanied with cardiac shock were induced by ligating coronary artery.Dogs were randomly divided into three groups:control group,fluid replacement group and Enalapril group.The hemodynamie indexes including mean arterial pressure(MAP),cardiac output (CO),right atrial pressure(RAP)and right ventrieular systolic pressure(RVSP)were measured before and immediately after RVMI model establishment,and 1 hour and 1 week after the treatment.The therapeutic effects were evaluated. Results After rapid fluid replacement treatment,RAP became higher and the hemodynamics deteriorated.After Enalapril treatment,RAP decreased and CO increased.Conclusion When RVMI in large area occurs,fluid replacement would further deteriorate the heart function of left and right ventricles when RAP≥13 mmHg,and Enulapril fluid replacement would reduce the right ventricle load and improve shock.