Olaleye Samuel Babafemi, Adaramoye Oluwatosin Adekunle, Erigbali Perebiri Peter, Adeniyi Olasupo Sunday
Gastrointestinal Research Unit, Department of Physiology, University of Ibadan, Ibadan, Nigeria.
World J Gastroenterol. 2007 Oct 14;13(38):5121-6. doi: 10.3748/wjg.v13.i38.5121.
To investigate the role of reactive oxygen species in the ulcer-aggravating effect of lead in albino rats.
Albino Wistar rats were randomly divided into three groups and treated orally with 100 mg/L (low dose) or 5000 mg/L (high dose) of lead acetate for 15 wk. A third group received saline and served as control. At the end of wk 15, colorimetric assays were applied to determine the concentrations of total protein and nitrite, the activities of the oxidative enzymes catalase and superoxide dismutase, and lipid peroxidation in homogenized gastric mucosal samples.
Exposure of rats to lead significantly increased the gastric mucosal damage caused by acidified ethanol. Although the basal gastric acid secretory rate was not significantly altered, the maximal response of the stomach to histamine was significantly higher in the lead-exposed animals than in the unexposed control group. Exposure to low and high levels of lead significantly increased gastric lipid peroxidation to 183.2%+/-12.7% and 226.1%+/-6.8% of control values respectively (P<0.0). On the other hand, lead exposure significantly decreased catalase and superoxide dismutase (SOD) activities and the amount of nitrite in gastric mucosal samples.
Lead increases the formation of gastric ulcers by interfering with the oxidative metabolism in the stomach.
研究活性氧在铅对白化大鼠溃疡加重作用中的作用。
将白化Wistar大鼠随机分为三组，分别口服100mg/L（低剂量）或5000mg/L（高剂量）醋酸铅，持续15周。第三组给予生理盐水作为对照。在第15周结束时，采用比色法测定匀浆胃黏膜样本中的总蛋白和亚硝酸盐浓度、氧化酶过氧化氢酶和超氧化物歧化酶的活性以及脂质过氧化水平。
大鼠接触铅显著增加了酸化乙醇引起的胃黏膜损伤。虽然基础胃酸分泌率没有显著改变，但接触铅的动物胃对组胺的最大反应明显高于未接触的对照组。低水平和高水平铅暴露分别使胃脂质过氧化显著增加至对照值的183.2%±12.7%和226.1%±6.8%（P<0.0）。另一方面，铅暴露显著降低了胃黏膜样本中过氧化氢酶和超氧化物歧化酶（SOD）的活性以及亚硝酸盐的含量。
铅通过干扰胃中的氧化代谢增加胃溃疡的形成。
