Small diameter vascular prosthesis with anti-clotting and anti-inflammatory response

保留血管内皮功能可能影响小口径移植物的早期和长期通畅。血管紧张素II诱导的内皮功能障碍的机制还不清楚。因此，我们评价了血管紧张素II和缬沙坦（血管紧张素II 1型受体阻断剂，ARB）对体外培养的大鼠主动脉环内皮依赖性舒张的影响。在麻醉的大鼠中切除椎间盘，切成环形段。将每个环在含0.5%小牛血清（含或不含血管紧张素II和缬沙坦）的Dulbecco改良Eagle培养基中于37℃下孵育24 h。采用器官浴法观察80 mmol/LKCl和300 nmol/L苯肾上腺素对心肌收缩的影响。用300 nmol/L苯丙氨酸收缩后，分别用硝普钠（10 <-11>~ 10 μ <-7>mol/L）或乙酰胆碱（10 <-9>~ 10 μ <-5>mol/L）测定舒张反应。血管紧张素Ⅱ（100 nmol/L）可增强苯肾上腺素引起的收缩反应。血管紧张素Ⅱ（100 nmol/L）对硝普钠有反应，但对乙酰胆碱无反应。然而，加入缬沙坦对乙酰胆碱有反应。缬沙坦对主动脉的内皮依赖性舒张作用得到改善。我们的结论是，在接受血管紧张素II的大鼠中，伐沙坦改善了主动脉的内皮依赖性舒张。

Preserving endothelial function of arterial conduits may affect early and long-term patency of small caliber grafts. Mechanism of angiotensin II-induced endothelial dysfunction is not well understood. So we evaluated the in vitro effects of angiotensin II and valsartan (angiotensin II type 1 receptor blocker, ARB) on the endothelium dependent relaxation of aortic ring from wister rats. The aortas which were excised in anesthetized rats cut into ring segments. Each ring was incubated for 24 h at 37℃ in Dulbecco's modified Eagle's medium containing 0.5% calf serum with or without angiotensin II and valsartan. Using an organ bath technique, contractile responses to 80mmol/L KCl and 300nmol/L phenylephrine were evaluated. And relaxation responses were examined using sodium nitroprusside (10^<-11> to 10^<-7>mol/L) or acetylcholine (10^<-9> to 10^<-5> mol/L) after contraction by 300nmol/L phenylephrine. Contractile response to phenylephrine was potentiated by angiotensin II (100nmol/L). Angiotensin II (100nmol/L) responded to sodium nitroprusside, but impaired relaxations to acetylcholine. However, adding valsartan responded to acetylcholine. The endothelium-dependent relaxation of the aorta by means of valsartan was improved. We conclude that Varsartan improved the endothelium-dependent relaxation of the aorta in rats that received angiotensin II.