This study aimed to determine if intrauterine-infused lipopolysaccharides (LPS) can be translocated to the mammary glands and induce an inflammatory response. Thirty-seven goats were divided into two experiments. Nineteen goats (control group, n = 9; LPS group, n = 10) were subjected to intravenous injection of LPS, and eighteen goats (control group, n = 8; LPS group, n = 10) were subjected to intrauterine infusion of LPS. Milk and blood samples were collected before and after the LPS challenge, to measure the blood leukocyte count (BLC), plasma LPS-binding protein (LBP), milk yield, milk somatic cell count (SCC), lactoferrin (LF), milk lactoperoxidase (LPO) activity, and pro- and anti-inflammatory cytokines in plasma and milk. Mammary gland tissues were collected from the parenchyma before and after the LPS challenge, for immunohistochemistry of LPS. In the intravenous injection experiment, the BLC (P < 0.001) and milk yield (P = 0.009) were lower, whereas the LF concentration (P < 0.001) and milk LPO activity (P < 0.001) were higher in the LPS group compared to that in the control group. LPS was detected in the mammary gland 3 and 24 h after intravenous injection of LPS. In the intrauterine infusion experiment, the mean concentrations of IL-1β and IL-6 in milk were higher in the LPS group compared to that in the control group (P = 0.004 and P = 0.017, respectively), whereas there were no changes in milk yield or SCC. LPS was detected in the connective tissues and interepithelial spaces of the alveoli of the mammary glands 24 h after intrauterine infusion of LPS. We conclude that intrauterine-infused LPS can be translocated to the mammary glands from the uterus, however, the amount of translocated LPS might not be enough to induce symptoms of clinical or subclinical mastitis.

中文翻译：

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宫内注射细菌性脂多糖对山羊乳腺炎症反应的影响。

这项研究旨在确定子宫内注入的脂多糖（LPS）是否可以易位到乳腺并引起炎症反应。将37只山羊分为两个实验。对十九只山羊（对照组，n = 9； LPS组，n = 10）进行LPS静脉注射，对十八只山羊（对照组，n = 8； LPS组，n = 10）进行宫内输注LPS 。在LPS攻击之前和之后收集牛奶和血液样本，以测量血白细胞计数（BLC），血浆LPS结合蛋白（LBP），牛奶产量，牛奶体细胞计数（SCC），乳铁蛋白（LF），牛奶乳过氧化物酶（LPO）活性以及血浆和牛奶中的促炎和抗炎细胞因子。在LPS攻击之前和之后，从薄壁组织中收集乳腺组织，用于LPS的免疫组化。在静脉注射实验中，与LPS组相比，LPS组的BLC（P <0.001）和牛奶产量（P = 0.009）较低，而LF浓度（P <0.001）和牛奶LPO活性（P <0.001）较高。在对照组中。静脉注射LPS后3和24 h在乳腺中检测到LPS。在子宫内输注实验中，LPS组的牛奶中IL-1β和IL-6的平均浓度高于对照组（分别为P = 0.004和P = 0.017），而在LPS组则没有变化。牛奶产量或SCC。子宫内注入LPS后24小时，在乳腺的结缔组织和上皮间间隙中检测到LPS。