Effects of valsartan on left cardiac function and vasoactive substance after acute myocardial infarction in rats

Objective To investigate the effects of valsartan on experimental left cardiac function and the vasoactive substance in rats with acute myocardial infarction (AMI).Methods Seventy Wistar rats were randomly divided into 6 group:①Sham groups: including Sham 1(n=5) and Sham 4(n=5).The pericardium of rats in Sham groups were cut open and sutured immediately.The rats were routinely breeded for 1 week and 4 weeks,1.5 mL saline was poured into stomach once a day.②Control groups: AMI 1 (n=10) and AMI 4 (n=10).Anterior descending branches of coronary artery of Wistar rats were ligated to establish models of AMI.The rats with AMI were poured into stomach with 1.5 mL saline once a day after AMI for 1 week and 4 weeks.③Valsartan groups: VAS 1 (n=10) and VAS 4 (n=10).The rats with AMI were poured into stomach with valsartan 10 mg·kg-1 and 1.5 mL saline for 1 week and 4 weeks(once a day).Cardiac function was assayed by arterial cannulatio.Angiotensin Ⅱ(Ang Ⅱ),aldosterone (ALD),endothelin (ET),thromboxane A2(TXA2) and prostacyclin I2 (PGI2) in serum were measured by radioimmunoassay.Results ① Valsartan could evidently improve cardiac function on the 1st and 4th week after experimental AMI.+dp/dtmax and-dp/dtmax were both increased on the 1st and 4th week and more evidently on the 4 week.②Compared with control groups,valsartan decreased the levels of ALD,ET and TXA2 in plasma and increased the levels of AngⅡ and PGI2 in plasma.Conclusion Valsartan could improve left cardiac function on late stage of infarction,the effect improve not only systolic function,but also diastolic function.