AimTo clarify the effects of myocardial apoptosis on ventricular remodeling after myocardial infarction, and to study the effects of mast cell degranulation on myocardial apoptosis and fibrosis.MethodsMyocardial infarction (MI) model was established in male Sprague-Dawley (SD) rats by ligation of left anterior descending coronary artery.The rats were randomly divided into three groups: sham-operated group (n＝6), MI model group (n＝8) and cromolyn sodium group (n＝7).Four weeks after ligation, myocardial apoptosis index (AI), collagen volume fraction (CVF) and expression level of caspase-3, Bcl-2 and Bax were obtained.ResultsCompared with sham-operated group, AI, CVF and expression level of caspase-3 and Bax in MI model group and cromolyn sodium group increased (P<0.05), but decreased in Bcl-2 (P<0.05).Cromolyn sodium group was decreased in these factors (P<0.05) compared with MI model group.Bcl-2 level in cromolyn sodium group was higher than MI model group, but there is no significant difference among these two groups (P＝0.127).The AI was positive correlation with CVF (r＝0.769, P<0.01).