Lin Sen, Hou Jia, Xiang Fang, Zhang Xiaoling, Che Lianqiang, Lin Yan, Xu Shengyu, Wu De, Fang Zhengfeng
Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China.
Anim Nutr. 2016 Jun;2(2):119-126. doi: 10.1016/j.aninu.2016.03.008. Epub 2016 Apr 16.
Mastitis is a common disease for mammals all around the world. Figuring out why mastitis mainly occurs around parturition may be helpful for dealing with the disease. Lipolytic activity and oxidative stress take place around parturition, which may leads to alteration in fatty acids profile and proinflammatory cytokine expression. Thus, the aim of the present study was to further our understanding about the high incidence of mastitis around parturition by comparison of plasma fatty acid profile and mammary inflammation indicators at different reproductive stages. A total of 47 female rats were included in the present study. After mating, all the pregnant and non-pregnant rats began to receive the same experimental diet. Blood samples were collected at day 1 and 14 of gestation as well as day 3 postpartum. Mammary samples were collected at day 14 of gestation and day 3 postpartum from pregnant and non-pregnant rats. The results showed that rats at d 3 postpartum had greater plasma concentrations of non-esterified fatty acids (NEFA), arachidonic acid (ARA) and docosahexaenoic acid (DHA) as well as ARA: eicosapentaenoic acid (EPA) ratio than those at d 14 of gestation. The mRNA abundances of interleukin-1β (), tumor necrosis factor-α (), and xanthine oxidoreductase () in mammary of the pregnant rats were greater than those in age-matched non-pregnant rats. Rats at d 3 postpartum had higher protein expression levels of IL-1β and TNF-α as well as meloperoxidase (MPO) activity and polymorphonuclear neutrophils (PMN) prevalence than those at d 1 of gestation. The rats at d 3 postpartum also had greater IL-1β and MPO activity than those at d 14 of gestation. The results indicated that elevated mammary expression of proinflammatory cytokines and as well as altered fatty acid profile around parturition might facilitate the recruitment of neutrophils into mammary glands.
乳腺炎是一种在全世界哺乳动物中都很常见的疾病。弄清楚乳腺炎为何主要发生在分娩前后可能有助于应对这种疾病。在分娩前后会发生脂解活性和氧化应激，这可能导致脂肪酸谱和促炎细胞因子表达的改变。因此，本研究的目的是通过比较不同生殖阶段的血浆脂肪酸谱和乳腺炎症指标，进一步了解分娩前后乳腺炎高发的原因。本研究共纳入47只雌性大鼠。交配后，所有怀孕和未怀孕的大鼠开始接受相同的实验饮食。在妊娠第1天和第14天以及产后第3天采集血样。从怀孕和未怀孕的大鼠中，在妊娠第14天和产后第3天采集乳腺样本。结果显示，产后第3天的大鼠血浆中游离脂肪酸（NEFA）、花生四烯酸（ARA）和二十二碳六烯酸（DHA）的浓度以及ARA与二十碳五烯酸（EPA）的比值均高于妊娠第14天的大鼠。怀孕大鼠乳腺中白细胞介素-1β（）、肿瘤坏死因子-α（）和黄嘌呤氧化还原酶（）的mRNA丰度高于年龄匹配的未怀孕大鼠。产后第3天的大鼠IL-1β和TNF-α的蛋白表达水平以及髓过氧化物酶（MPO）活性和多形核中性粒细胞（PMN）患病率均高于妊娠第1天的大鼠。产后第3天的大鼠IL-1β和MPO活性也高于妊娠第14天的大鼠。结果表明，分娩前后乳腺促炎细胞因子表达升高以及脂肪酸谱改变可能有助于中性粒细胞募集到乳腺中。
