中文摘要：

将40只雌性ICR小鼠，受孕后随机分为试验组和对照组。雌鼠产后10-11d，试验组经第4对乳头灌注LPS，对照组灌注生理盐水，分别于灌注后不同时间采集样本，组织学分析乳腺病理变化；分析对各组乳腺组织中TLR4和TNF-α mRNA表达变化。组织学结果显示，灌注1．5h后乳腺组织中炎性细胞增多，6、12h乳腺腺泡内有大量的炎性细胞浸润，腺泡结构崩解；6h TLR4 mRNA表达极显著高于对照组（P〈0．01）；4个试验组中TNF-αmRNA表达极显著高于对照组（P〈0．01）。试验结果表明LPS能够增强TLR4和TNF-α mRNA表达。

英文摘要：

Forty ICR female mice were divided into experimental group and control group after conception. On days 10 to 11 of lactation,mice were infused with either LPS solution or saline solution through papillary duct. The tissue samples of mammary glands were taken at different hours, and the pathological changes of mammary gland were ana- lyzed by histological methodology. TLR4 and TNF-α mRNA expression were analyzed by RT-PCR. The result showed that infiltrating inflammatory cells in the mammary glands increased at 1.5 h after intramammary infusion of LPS. The mammary by large number of inflammatory cells were infiltrated in glands and normal alveolar architecture was lost at 6 h, 12 h after injection. The expression of TLR4 mRNA at 6 h after intramammary infusion was signifi- cantly higher than that of control （P〈0.01）. TNF-α mRNA expression in experimental group was also significantly higher than that of control （P〈0.01）. The results indicated that LPS could enhance the expression of TLR4 and TNF-α mRNA levels.