The expression of endothelial and inducible nitric oxide synthase and apoptosis in intestinal ischemia and reperfusion injury under the action of ischemic preconditioning and pentoxifylline

Abstract Purpose: To investigate the expression of nitric oxide synthase (NOS) and apoptosis associated with ischemic preconditioning (IPC) and pentoxifylline (PTX) in intestinal ischemia (I) and reperfusion (R) injury. Methods: Thirty male rats were assigned to 5 groups: (CG), no clamping of the superior mesenteric artery (90 minutes); (IR-SS) saline + ischemia (30 minutes) + reperfusion (60 minutes); (IR-PTX) PTX + ischemia (30 minutes) + reperfusion (60 minutes); (IPC-IR-SS) 5 minutes of ischemia + 5 minutes of reperfusion (IPC) + saline + I(30 minutes)+R(60 minutes); and (IPC-IR-PTX) IPC + PTX + I(30 minutes)+ R(60 minutes). Results: The application of IPC and PTX showed a significantly lower immunohistochemistry reaction for active caspase-3 (P<0.05) compared to IR+SS. The number of cells immunoreactive to BCL-2 was higher in the IR-PTX group (P>0.05). The NOS-2 expression (qRTPCR) in the IR-PTX group (P<0.05) was higher than the values for the IPC+IR-SS and IPC-IR-PTX groups. The NOS-3 expression was significantly upper in the IPC-IR-PTX group than in the CG (P<0.05), the IR-SS (P<0.05) and the IR-PTX (P<0.05) groups. Conclusions: The BCL-2 and active caspase-3 showed beneficial effects on PTX and IPC. The expression of NOS-2 and NOS-3 in the IPC and IPC-PTX groups showed no synergistic effect.

摘要
目的：探讨缺血预处理（ischemic preconditioning, IPC）联合己酮可可碱（pentoxifylline, PTX）对肠缺血再灌注损伤中一氧化氮合酶（nitric oxide synthase, NOS）的表达及细胞凋亡的影响。
方法：将30只雄性大鼠随机分为5组：（CG组）假手术组，不夹闭肠系膜上动脉，持续90分钟；（IR-SS组）生理盐水+缺血（30分钟）+再灌注（60分钟）；（IR-PTX组）己酮可可碱+缺血（30分钟）+再灌注（60分钟）；（IPC-IR-SS组）先给予5分钟缺血+5分钟再灌注的缺血预处理，随后生理盐水+缺血（30分钟）+再灌注（60分钟）；（IPC-IR-PTX组）缺血预处理+己酮可可碱+缺血（30分钟）+再灌注（60分钟）。
结果：与IR-SS组相比，IPC联合PTX干预后，活化半胱天冬酶-3（active caspase-3）的免疫组化反应强度显著降低（P<0.05）。IR-PTX组中B细胞淋巴瘤因子2（B-cell lymphoma 2, BCL-2）免疫阳性细胞数更高，但差异无统计学意义（P>0.05）。实时定量聚合酶链反应（quantitative real-time polymerase chain reaction, qRT-PCR）检测显示，IR-PTX组的一氧化氮合酶-2（nitric oxide synthase 2, NOS-2）表达水平高于IPC-IR-SS组与IPC-IR-PTX组，差异具有统计学意义（P<0.05）。IPC-IR-PTX组的一氧化氮合酶-3（nitric oxide synthase 3, NOS-3）表达水平显著高于CG组、IR-SS组及IR-PTX组（P<0.05）。
结论：己酮可可碱与缺血预处理可通过调控BCL-2及活化半胱天冬酶-3的表达发挥组织保护作用。缺血预处理组及缺血预处理联合己酮可可碱组中，NOS-2与NOS-3的表达未表现出协同效应。