大鼠肝脏脂氧合酶活性及其协同氧化联苯胺能力的实验研究

作者通过体外实验方法测定大鼠肝组织中的脂氧合酶活性。结果表明:肝细胞浆组分中的脂氧合酶既可催化O_2插入亚油酸分子中的双加氧反应,形成氢过氧化物,又可在供氢体联苯胺存在条件下,使上述产物羟化,并将联苯胺协同氧化。当亚油酸和H_2O_2共存时,该酶这一协同氧化能力明显增强。提示脂氧合酶可能参与某些致癌物的代谢过程,有重要的毒理学意义。

Experimental Study of Lipoxygenase Activity from Rat Liver and its Capability Towards the Co-oxidation of Benzidine

Lipxygenase activity from rat liver cytosol was measured by spectrophotometry. The results demonstrated the existence of lipoxygenase in rat liver. It catalyzed the reactions of linoleic acid and benzidine converting into lipid hydroperoxide and benzidinediimine separately. The optium conditions for the both reactions were pH 7.2 in Tris buffer, 3. 5 mM linoleic acid and 0.64 mg rat liver cytosolic protein. These enzymatic reactions were inhibited by nordihydroguairetic acid (NDGA) in a concentration dependent manner. Futhermore, in the presence of 3.5 mM linoleic acid, 5 mM H_2O_2 at pH 7.2, the co-oxidation of benzidine was significantely incresed than in the presence of linoleic acid or H_2O_2 alonQe. This suggested a possible synergistic interaction between lipid hydroperopxide and H_2O_2 in terms of cooxidation of xenobiotics.