could anyone help me correct the following abstract?
An experimental study of the relation between Cilazapril、Valsartan and the expressions of atrial Calpains, and the relation between Cilazapril、Valsartan and atrial structural remodeling in atrial fibrillation dogs
【Abstract】Objective The present study was designed to evaluate the effects of cilazapril and valsartan on the mRNA and protein expressions of atrial CalpainⅠ、CalpainⅡmRNA and atrial structural remodeling in atrial fibrillation (AF) dogs induced by chronic rapid atrial pacing. Methods Twenty-seven dogs were randomly divided into sham-operated group (n=6), control group (n=7), cilazapril group (n=7) and valsartan group (n=7). The dogs in control group, cilazapril group and valsartan group were subjected to rapid atrial pacing at 400 bpm for 6 weeks, whereas the pacemakers in sham-operated group did not work. The dogs in cilazapril and valsartan groups were given cilazapril (1mg·kg-1·d-1)or valsartan(30mg·kg-1·d-1) 1 week before pacing respectively until pacing stopped. Transthoracic and transoesophageal echocardiographic examinations were performed in order to detect the changes of left atrium volume and contractile function. The inducibility and duration of AF were measured in all groups. The expressions of atrial calpain I and calpain II mRNA were semi-quantified by reverse transcription-polymerase chain reaction. The protein levels of calpain I and calpain II in atrial myocardium were measured by Western-blot method. Pathohistological and ultrastructural changes in atrial tissue were assessed by light and electron microscopy. Results After 6-week pacing, the mRNA and protein expressions of calpain I were up-regulated dramatically in the control group than those in the sham-operated group, and calpain I protein expression in all groups highly correlated with the myolysis (r=0.89, P＜0.01). Cilazapril and valsartan could significantly inhibit the mRNA and protein expressions of calpain I. No differences were found in the expression of calpain II mRNA and