槲皮素对X射线照射后大鼠免疫功能的影响

Protective effects of Quercetin to 6 Gy irradiated rats

目的 探讨槲皮素（QN）对6 Gy X射线照射后大鼠免疫功能及肝脏氧化应激反应的影响。方法 40只大鼠随机分成4组，每组10只，第1组连续7d腹腔内注射生理盐水（0．5ml／150g体重）作为对照组，第2组（QN组）连续7d用槲皮素（40mg／kg体重）腹腔注射，第3组用单次6 Gy X射线照射，第4组（6 Gy＋QN组）连续7d腹腔注射槲皮素（40mg／kg体重），在最后一次注射后1h，给予单次6 Gy X射线照射。照射后24h，将大鼠麻醉后断头处死，取其脾脏用四甲基偶氮唑盐（MTT）法检测淋巴细胞转化率，流式细胞术检测CD；CD8^＋及CD4^＋／CD8^＋T淋巴细胞的变化，取肝脏检测氧化应激反应并观察一般状态变化。结果 经QN预先处理组的大鼠脾脏淋巴细胞转化率显著高于6 Gy照射组，CD4^＋、CD8^＋及CD4^＋，CD8^＋T淋巴细胞百分率亦显著高于单纯照射组（F值分别为8．455、22．644和18．911，P〈0．01），尤其以增加CD4^＋T淋巴细胞百分率为显著。同时发现QN预先处理的照射组大鼠肝脏丙二醛（MDA）含量显著低于照射组（F=10．059，P〈0．01），抗氧化酶类超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH—Px）活性和抗氧化物质GSH含量显著高于照射组（F值分别为23．688、186．046和19．788，P〈0．01）。6 Gy照射组大鼠肝脏肝小叶中心静脉扩张，肝血窦明显充血，并有炎性细胞浸润，而经QN处理后的照射组大鼠肝脏，肝小叶中心静脉轻度扩张，肝血窦充血较6 Gy照射组明显减轻。结论 槲皮素对X射线照射后大鼠免疫功能具有明显增强作用，并显著改善了照射大鼠肝脏的氧化应激损伤，对6 Gy照射大鼠起到了一定程度的保护作用。

Objective To evaluate the radioprotective effects of Quercetin （QN） on 6 Gy X-ray irradiation-induced immune dysfunction and toxicity in hepatic tissue in rats. Methods 40 adult rats were randomly divided into 4 groups. Group Ⅰ was injected intraperitoneally with saline solution for 7 consecutive days and served as control group. Group Ⅱ was daily injected with QN （40 mg/kg） for 7 consecutive days. Group Ⅲ was irradiated with a single dose of 6 Gy X-ray. Group Ⅳ received a daily injection of QN （40 mg/kg） for 7 consecutive days, and 1 h after the last injection rats were irradiated with a single dose （6 Gy） X-ray irradiation. The animals were sacrificed after 24 h. Lymphocyte transforming rate was measured with MTT＇ method, and CD4^＋ T, CD8^＋; T and CD4^＋/CD8^ T were measured with flow cytometry method. Oxidative conditions in liver were measured with malondialdehyde （MDA）, reduced glutathione hormone （GSH）, superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px） activities kits. HE staining was used to observe the general condition of rat＇s liver. Results Lymphocyte transforming rate, CD4^＋ T, CD^8＋ T and CD^4＋/CD8^ T in rats of Group IV were all higher than those in rats of Group Ⅲ（ F = 8.455,22.644,18.911, P 〈 0.01 ）. MDA content in the Group Ⅳ rat＇ s liver was lower than that in the Group Ⅲ （ F = 10.059, P 〈 0.01 ） and antioxidant enzymes SOD, GSH-Px activities were higher than those in Group Ⅲ（ F = 23.688,186.046,19.788, P 〈 0.01）. The capillary of the hepatic lobules dilated and congested obviously in portal area, involving infiltration of polymorphonuclear leukocytes in the Group Ⅲ, while QN improved this change apparently. Conclusions Pretreatment with Quercetin improved the irradiated rat＇ s immune functions and protected the irradiated rats from oxidative stress to some extent.