Endothelial nitric oxide synthase is protective in the initiation of caerulein-induced acute pancreatitis in mice
Endothelial nitric oxide synthase is protective in the initiation of caerulein-induced acute pancreatitis in mice
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DOI：
10.1152/ajpgi.00525.2003
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发表时间：
2004-07-01
影响因子：
4.5
通讯作者：
Owyang, C
中科院分区：
文献类型：
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作者：
DiMagno, MJ;Williams, JA;Owyang, C
抑制一氧化氮（NO）合酶（NOS）或增强NO对急性胰腺炎（AP）过程的影响是有争议的，部分原因是存在三种NOS同工型：神经型（nNOS）、内皮型（eNOS）和诱导型（iNOS）。我们研究了是否抑制或选择性基因缺失的NOS亚型修改的启动阶段的雨蛙素诱导的AP小鼠，并探讨这是否影响胰腺微血管血流（PMBF）。我们使用体内和体外模型研究了用N-ω-硝基-L-精氨酸（L-NNA; 10 mg/kg ip）或靶向缺失eNOS、nNOS或iNOS基因对小鼠雨蛙素诱导的AP起始阶段的非特异性NOS抑制的影响。进行蛋白质印迹分析以评估eNOS磷酸化状态，这是酶活性的指标，并且使用微球研究来测量PMBF。L-NNA和eNOS缺失，但不是nNOS或iNOS缺失，胰蛋白酶活性和血清脂肪酶在体内雨蛙素诱导的AP的起始阶段增加。L-NNA和eNOS不影响胰蛋白酶的活性，在雨蛙素过度刺激的孤立腺泡，这表明非腺泡事件介导的NOS封锁在体内的效果。野生型小鼠AP的起始阶段与eNOS Thr（495）残基去磷酸化相关，这伴随着eNOS激活，PMBF增加178%;这些效应在eNOS缺失小鼠中不存在。因此，eNOS是影响雨蛙素诱导的AP起始的主要亚型。eNOS衍生的NO通过作用于非腺泡细胞类型（最可能是内皮细胞）产生更大的PMBF而发挥保护作用。
The effect of inhibiting nitric oxide ( NO) synthase ( NOS) or enhancing NO on the course of acute pancreatitis (AP) is controversial, in part because three NOS isoforms exist: neuronal ( nNOS), endothelial ( eNOS), and inducible ( iNOS). We investigated whether inhibition or selective gene deletion of NOS isoforms modified the initiation phase of caerulein-induced AP in mice and explored whether this affected pancreatic microvascular blood flow (PMBF). We investigated the effects of nonspecific NOS inhibition with N-omega-nitro-L-arginine (L-NNA; 10 mg/kg ip) or targeted deletion of eNOS, nNOS, or iNOS genes on the initiation phase of caerulein-induced AP in mice using in vivo and in vitro models. Western blot analysis was performed to assess eNOS phosphorylation status, an indicator of enzyme activity, and microsphere studies were used to measure PMBF. L-NNA and eNOS deletion, but not nNOS or iNOS deletion, increased pancreatic trypsin activity and serum lipase during the initiation phase of in vivo caerulein-induced AP. L-NNA and eNOS did not affect trypsin activity in caerulein-hyperstimulated isolated acini, suggesting that non-acinar events mediate the effect of NOS blockade in vivo. The initiation phase of AP in wild-type mice was associated with eNOS Thr(495) residue dephosphorylation, which accompanies eNOS activation, and a 178% increase in PMBF; these effects were absent in eNOS-deleted mice. Thus eNOS is the main isoform influencing the initiation of caerulein-induced AP. eNOS-derived NO exerts a protective effect through actions on nonacinar cell types, most likely endothelial cells, to produce greater PMBF.