甘氨酸对大鼠非酒精性脂肪性肝病肝组织COX-2表达的影响

Effect of glycine on COX-2 expression in the rat nonalcoholic fatty liver

目的观察甘氨酸(Gly)对非酒精性脂肪性肝病大鼠肝组织环氧合酶-2(COX-2)表达的影响。方法通过高脂饮食建立大鼠非酒精性脂肪性肝病模型,并在第8,12,16周末分批处死大鼠,同期设正常饮食组作为对照组和高脂+甘氨酸饮食的治疗组。测定血浆内毒素(ET)和肝组织匀浆丙二醛(MDA);肝组织切片行HE染色和COX-2免疫组织化学染色。结果模型组肝组织MDA于12周开始明显升高(P<0.05);血浆ET水平在8,12周末模型组较同期对照组、治疗组升高并不明显(P>0.05),在16周末模型组高于同期对照组和治疗组(P<0.05);COX-2在8,12周三组表达均为阴性,16周模型组织COX-2表达呈阳性。结论在非酒精性脂肪性肝病发生发展中伴有肠源性内毒素血症(IETM),Gly可降低ET水平和肝组织MDA含量,下调肝组织COX-2的表达,减轻肝脏的脂肪变性。

Objective To explore the effect of glycine on ODX-2 expression in liver tissue of rats with non-alcoholic fatty liver disease （NALFD）. Methods Fifty-four rats were randomly divided into 3 groups： control group, model group（high fat-fed） and treatment group（high fat-fed ＋ glycine）. These rats were sacrificed at the end of weeks 8,12,16. The blood of abdominal aorta was obtained, and the levels of serum ET and MDA in liver were measured. Histopathology of liver tissue was analyzed by light micro- scope, and ODX-2 expression in liver tissue was detected by immunohistochemistry. Results The serum MDA of the liver tissue increase significantly at week 12 in model group（ P 〈 0.05）. Compared with control group and treatment group, serum endotoxin significantly increased at week 16（P〈0.05）, while it increased at the end d weeks 8,12, but there was no significant difference. ODX-2 expression was negative in 3 groups at the end of weeks 8 and 12 by immunohistochemistry. But ODX-2 expression was positive in model group and treatment group at the end of week 16, and there was significant difference among 3 groups （P〈0.05）. Conclusion Non-alcoholic fatty liver disease accompanies intestinal endotoxemia, and glycine could attenuate the levels of endotoxemia, MDA, and the expression of ODX-2, which could prevent NALFD.