没食子酸酯对羟自由基损伤抗凝血酶Ⅲ的保护作用

Protective effect of gallic esters against hydroxyl radical damage on antithrombin Ⅲ

ＣｕＣｌ＿２／抗坏ＭＫ体系产生的羟自由基（·ＯＨ）在离体条件下可抑制血浆及纯品抗凝血酶Ⅲ（ＡＴ－Ⅲ）活性，诱发ＡＴ－Ⅲ纯品解聚，这种损伤呈明显的量效。时效关系。且血浆稀释度越高。ＡＴ－Ⅲ损伤越重。０．１－０．６ｍｍｏｌ·Ｌ￣（－１）没食子酸乙酯。丙酯和异丁酯抑制血浆ＡＴ－Ⅲ氧化呈量效关系。０．６ｍｍｏｌ·Ｌ￣（－１）时，上述三种酯对ＡＴ－Ⅲ氧化的抑制率依次为４８．５％，３９．１％和４０．０％，比较结果表明。这些酯与另三种抗血栓药抑制ＡＴ－Ⅲ纯品解聚的作用强度为川芎嗪＜阿魏酸钠＜儿茶精＜没食子酸酯．

The activities of plasma antithrombin Ⅲ(AT-Ⅲ),crude or purified,can be in-hibited by hydroxyl radical produced byCuCl_2/ascorbic acid svstem in vitro,and the purifiedAT-Ⅲ also can be cleavaged by this system,The inhi-bition was dosage-and time-dependent.The higherthe dilution of plasma, the heavier the AT-Ⅲdamagewas observed. The protective effects of 0-0.6mmol·L￣(-1)ethyl gallate, propyl gallate and isobutyl gallateagainst plasma AT-Ⅲ oxidation were dosage-depen-dent. At 0.6mmol·￣(-1),the protection percentageagainst plasma AT-Ⅲ oxidation of these esters wereethyl gallate 48.5%,propyl gallate 39.1%and isobutylgallate 40.0%,respectively. The order of the protectivepotency of these esters and other three anti-thrombotic drugs was pyrazine < sodium ferulate <catechuicine<gallic esters.