Pawlik W W, Gustaw P, Thor P, Sendur R, Czarnobilski K, Hottenstein O D, Konturek S J
Institute of Physiology, University School of Medicine, Krakow, Poland.
J Physiol Pharmacol. 1993 Jun;44(2):139-46.
The aim of the study was to determine the role of endogenous nitric oxide (NO) as the mediator of intestinal blood flow and motility. Experiments were performed on anesthetized rats. Blood flow in the jejunum was determined by Laser-Doppler flowmeter. Motility was monitored on the basis of changes in intrajejunal pressure. Systemic arterial pressure was also recorded. To investigate the potential role of nitric oxide in the regulation of basal intestinal blood flow and motility the NO synthase inhibitor NG-nitro-L-arginine (L-NNA) was given systemically. Intravenous bolus of L-NNA (15 mg/kg) reduced basal intestinal blood flow and increased both intestinal motility and arterial pressure in the dose-dependent manner. To test the specificity of the NO synthase blockade we administered L-arginine alone or in combination with L-NNA. Pretreatment with L-arginine (100.0 mg/kg i.v.) alone had no major influence but when combined with L-NNA it reversed the intestinal circulatory and motor effects of L-NNA. The results of these studies suggest that endogenous NO exerts a tonic relaxatory influence on the smooth muscle of the intestinal vessels and intestinal wall.
该研究的目的是确定内源性一氧化氮（NO）作为肠血流和蠕动介质的作用。实验在麻醉大鼠身上进行。空肠血流通过激光多普勒血流仪测定。根据空肠内压力变化监测蠕动。还记录了体循环动脉压。为了研究一氧化氮在基础肠血流和蠕动调节中的潜在作用，全身给予一氧化氮合酶抑制剂NG-硝基-L-精氨酸（L-NNA）。静脉推注L-NNA（15mg/kg）以剂量依赖方式降低基础肠血流，并增加肠蠕动和动脉压。为了测试一氧化氮合酶阻断的特异性，我们单独给予L-精氨酸或与L-NNA联合给药。单独用L-精氨酸（100.0mg/kg静脉注射）预处理没有重大影响，但与L-NNA联合使用时，它逆转了L-NNA对肠道循环和运动的影响。这些研究结果表明，内源性NO对肠血管和平滑肌施加了紧张性舒张作用。
