Beta Blockers After Acute Myocardial Infarction Myocardial Apoptosis And Related Gene Expression In The Role Of Research

Cardiomyocyte Apoptosis and Apoptosis Related Gene Expression after Acute Myocardial Infarction in RatsObjective To investigate cardiomyocyte apoptosis and the expressions of caspase-3, bcl-2 and bax after acute myocardial infarction (AMI) in rats.Methods AMI model was established with the ligation of anterior descending coronary artery in 78 randomly selected female SD rats. Twenty-four hours after operation, the 43 survivors were randomly divided into 48-hour and 4-week two groups according to the time to observe, that is: MI48h (n=11) and MI4w (n=13) groups, Sham-operated rats (S, n=27) were also randomly selected and reassigned to S48h (n=10) and S4w (n=10) groups. Cardiomyocyte apoptosis was detected with In situ terminal deoxynucleotidyl transferase (TdT)-dUTP nick-end labeling (TUNEL staining) and DNA gel electrophoresis. Caspase-3, bcl-2 and bax was detected with immunohistochemistry and Western blot analysis.Results Compared with sham-operated group, after AMI, systolic, diastolic , and mean arterial blood pressures (SBP, DBP, MAP), left ventricular systolic pressure (LVSP) and the maximum change rate of left ventricular pressure rise and fall (±dp/dt) were significantly decreased (P<0.05~0.01), while left ventricular end diastolic pressure (LVEDP) was significantly increased (P<0.05) in MI48h group; All the above indices had the same change as that of MI48h group, with the LVEDP significantly higher (P<0.01), except for a non-significantly change in SBP, DBP and MAP(all P>0.05) in MI4w group,. Mean while in both MI48h and MI4w groups, when myocyte necrosis and scar formation occurred in the infracted area, myocyte apoptotic index was significantly increased in the infracted/scar, border and non-infarcted areas (P<0.05~0.01); Caspase-3 and bax expressions were significantly increased (P<0.05~0.01) in myocytes of the above three areas; Bcl-2 expression was...