缬沙坦对大鼠急性心肌梗塞后左室功能及血管活性物质的影响

目的：探讨缬沙坦对实验性急性心肌梗塞（AMI）大鼠左心室功能和血管活性物质的影响。方法： 70只Wistar大鼠随机分成6组:①假手术对照组,Sham 1（n=5）和Sham 4（n=5），合称Sham组，开胸打开心包后立即缝合，用生理盐水1.5 mL灌胃(每日1次),分别常规饲养1和4周。②对照组AMI 1（n=15）和AMI 4（n=15），大鼠结扎冠状动脉前降支建立AMI模型后立即用生理盐水1.5 mL灌胃(每日1次)，分别常规饲养1和4周。③缬沙坦1周组VAS 1（n=15）及4周组VAS 4（n=15），AMI造模后立即用缬沙坦10 mg?kg^-1加生理盐水1.5 mL灌胃1或4周(每日1次)。进行下列指标测定：动脉插管测定心功能，放免法测定血浆血管紧张素Ⅱ（AngⅡ）、醛固酮（ALD）、内皮素（ET）、血浆血栓素A₂ (TXA₂)及前列腺素I₂ (PGI₂)。结果：①应用缬沙坦1周和4周后左室最大收缩、舒张压力微分（±dp/dt_max）明显升高；②与AMI对照组比较，缬沙坦能降低血浆ALD、ET及TXA₂水平，使AngⅡ及PGI₂升高。结论：缬沙坦对AMI后左室收缩及舒张功能均有改善作用。

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.