El-Newihi H M, Kanji V K, Mihas A A
Division of Digestive Diseases, Veteran Affairs Medical Center, Jackson, Mississippi, USA.
Am J Gastroenterol. 1996 Mar;91(3):535-8.
The importance of portal hypertensive gastropathy, as a potentially bleeding lesion in cirrhotics with portal hypertension, has recently been appreciated. Histologically, dilation of the mucosal and submucosal vessels of the stomach is noted in this entity. The possibility of nitric oxide acting as a mediator for this mucosal vascular dilation has not been explored.
We determined, in a group of 10 male cirrhotic patients with esophageal varices and endoscopic changes consistent with severe portal hypertensive gastropathy (Group A), the gastric mucosal nitric oxide synthase activity. This was determined by measuring the rate of conversion of [3H]-arginine to [3H]-citrulline. Serum levels of nitrates and nitrites, the end products of nitric oxide, were also measured. The results were compared with those of a group of 10 male controls with no liver disease (Group B).
Gastric mucosal constitutive and inducible nitric oxide synthase levels were significantly higher in group A (125.4 +/- 4.3 and 259.7 +/- 5.5 pmol/mg protein/minute, respectively) than in group B (88 +/- 8.6 and 130.8 +/- 6.6 pmol/mg protein/minute, respectively) ( p < 0.002 and < 0.0001, respectively). Serum nitrate/nitrite levels were 30.1 +/- 3.2 nmol/ml in group A and 15.5 +/- 0.09 nmol/ml in group B (p < 0.001).
We conclude that the significantly increased gastric mucosal nitric oxide synthase activity, in patients with portal hypertensive gastropathy, suggests an important role for nitric oxide in the pathogenesis of this mucosal lesion.
门脉高压性胃病作为门脉高压肝硬化患者潜在的出血性病变，其重要性最近已得到认识。组织学上，在该病变中可见胃黏膜和黏膜下血管扩张。一氧化氮作为这种黏膜血管扩张介质的可能性尚未被探讨。
我们测定了一组10例患有食管静脉曲张且内镜检查结果符合重度门脉高压性胃病的男性肝硬化患者（A组）的胃黏膜一氧化氮合酶活性。通过测量[3H]-精氨酸向[3H]-瓜氨酸的转化速率来确定。还测量了一氧化氮的终产物硝酸盐和亚硝酸盐的血清水平。将结果与一组10例无肝病的男性对照者（B组）的结果进行比较。
A组胃黏膜组成型和诱导型一氧化氮合酶水平（分别为125.4±4.3和259.7±5.5 pmol/mg蛋白/分钟）显著高于B组（分别为88±8.6和130.8±6.6 pmol/mg蛋白/分钟）（p分别<0.002和<0.0001）。A组血清硝酸盐/亚硝酸盐水平为30.1±3.2 nmol/ml，B组为15.5±0.09 nmol/ml（p<0.001）。
我们得出结论，门脉高压性胃病患者胃黏膜一氧化氮合酶活性显著增加，提示一氧化氮在这种黏膜病变的发病机制中起重要作用。
