氧自由基在应激性胃溃疡中的发病学意义

本工作研究了氧自由基在大鼠冷冻束缚应激性胃溃疡中的发病学意义。实验结果如下:(1)以超氧自由基清除剂超氧化物歧化酶(SOD)或羟自由基清除剂二甲亚砜和甘露醇预先处理大鼠,均可显著地减轻胃粘膜损伤;(2)应激时,胃粘膜内的脂质过氧化分解产物丙二醛的含量显著升高;(3)组织化学的研究显示,胃粘膜层含有丰富的黄嘌呤氧化酶,其活性在应激时明显升高,预先用别嘌呤醇处理大鼠以抑制黄嘌呤氧化酶的活性,可使胃粘膜损伤显著减轻。上述结果提示,氧自由基是应激性胃溃疡的重要致病因子,而黄嘌呤氧化酶活性的升高似可能为应激时氧自由基生成增加的重要原因。

ROLE OF OXYGEN--DERIVED FREE RADICALS IN STRESS-INDUCED GASTRIC ULCERATION

In the prerent work, the role of oxygen-derived free radicals in the pathogenesis ofthe gastric mucosal injury induced by cold--restraint stress was studied in rats. The re-sults were as follows. (1) In rats pretreated with superoxide dismutase (SOD), a scav-enger of superoxide anions, or with dimethyl sulfoxide and mannitol, scavengers of hy-droxyl radicals, the gastric lesions induced by stress became much less extensive. (2)The mucosal content of malondialdehyde, a metabolic product of lipid peroxides, wassignificantly increased during stress. (3) Histochemical study revealed that the gastricmucosa abounded in xanthine oxidase (XO), the enzymic activity of which was increased during stress. In the rats pretreated with allopurinol, to inhibit XO activity, theextent of gastric mucosal lesions was decreased significantly. These suggested that oxy-gen free radicals might be one of the important factors in inducing gastric mucosal injury during stress and the increase of XO activity might be responsible for the produc-tion of the radicals.