LPS对小鼠乳腺组织中NF—KB、ACCa和β-CaseinmRNA表达的影晌

为探讨灌注不同质量浓度LPS对小鼠乳腺组织中NF-xB、ACCa和pCaseinmRNA表达的影响，选择30只雌性ICR小鼠为试验动物，受孕后随机分为试验组和对照组，试验组经第4对乳头灌注不同质量浓度LPS（0．1，5，10，50，100mg／L），对照组灌注生理盐水，于灌注后6h采集乳腺组织样品，组织学方法分析乳腺组织的病理变化；采用RT—PCR方法分析乳腺组织中NF_KB、ACCa和B—CaseinmRNA表达的变化。病理切片结果显示，随着LPS灌注浓度的增加，乳腺小叶间炎性细胞数量逐步增加，乳腺小叶内腺泡结构破坏程度也变大；对乳腺组织中NF-xB、ACCa和pCasein的mRNA表达水平进行分析时，发现灌注LPS小鼠乳腺组织中NF-KBmRNA的表达水平随着LPS灌注浓度的增加而逐步增加，而ACCa和pCaseinmRNA的表达水平则随着LPS灌注浓度的增加而逐步降低。结果表明，灌注LPS能够上调N-KBmRNA的表达，下调ACCa和肛CaseinmRNA的表达。

Effect of LPS on NF-kB,ACCa and β-Casein mRNA expression in mammary glands of mice

Lipopolysaccharide （LPS） is the main component of cell wall of Gram-negative bacteria. It can activate the release of inflammatory cytokines, and give rise to extensive and intensive inlammatory response. The objective of this experiment was to investigate the effects of LPS infusion on mRNA expression of NF-kB,ACCa and β-Casein in mammary glands of mice. Thirty ICR female mice were divided into control group and experimental group after conception. On days 10 to 11 of lactation,two abdominal mammary glands （L4 and R4） of mice were infused with 0.1 mL of either LPS solution （0.1,5,10,50,100 mg/L） or saline solution through needle. At 6 h after in- fusion the mammary gland tissue samples were taken, and the pathological changes of mammary gland were observed by histological methodology. NF-kB, ACCa and β-Casein mRNA expression were analyzed by RT-PCR. The result of pathological section showed that the number of inflam matory cells between lobules of mammary gland tissues raised gradually with the increase of infu sion concentration of LPS,and the damage extent of acinus structure in lobules of mammary gland tissues increased gradually as well. The mRNA expression level of NF-nB raised gradually with the increase of infusion concentration of LPS, meanwhile the mRNA levels of ACCa and D-Casein de creased with the increase of infusion concentration of LPS. The result indicated that infusion of LPS could up-regulate mRNA expression of NF-kB, while down-regulate mRNA expression of ACCa and D-Casein.