Abstract：
The early period of mammary gland involution is a critical juncture in the lactation cycle that can have significant effects on milk production and mammary gland health. Pegbovigrastim (PEG) administered 1 wk prior and on the day of parturition can enhance immune function and reduce the incidence of mastitis in the early postpartum period. Oxylipids are potent metabolites of polyunsaturated fatty acids (PUFA) and are important mediators of inflammation. The objective of this study was to evaluate effects of PEG given 1 wk before and at the day of dry-off (D0) on concentrations of oxylipids in plasma and milk from 7 d before D0 to 14 d after, as well as the effects during the first 14 d of the subsequent lactation. We hypothesized that both pro- and anti-inflammatory oxylipids would vary based on initiation of mammary gland involution and that pegbovigrastim would affect oxylipid concentrations, particularly those related to leukocytes. A complete randomized blocked design was used to enroll cows into either a PEG treatment group (n = 10) or control group (n = 10; CON). Blood samples were collected -7, -2, -1, 0, 1, 2, 4, 7, and 14 d relative to dry-off and 5, 10, and 14 d postcalving. Samples were analyzed for PUFA and oxylipids in milk and plasma by ultra-performance mass spectrometry and liquid chromatography tandem quadrupole mass spectrometry, respectively. Overall, 30 lipid mediators were measured in both milk and plasma. Repeated measures analyses revealed a significant interaction of treatment by time for milk 8-iso-keto-15-prostaglandin E2, prostaglandin F2α, plasma 8,12-iso-prostaglandin Fα-VI, 11-hydroxyeicosatetraenoic acid, and 12-hydroxyheptadecatienoic acid. The majority of milk PUFA and oxylipids differed significantly during early mammary gland involution and into the early postpartum period. This study demonstrated changes in oxylipids in milk secretions and plasma during early involution, and further investigation may illuminate multiple complex processes and reveal targets for optimization of mammary gland involution.
摘要：
乳腺退化的早期是泌乳周期中的关键时刻，会对产奶量和乳腺健康产生重大影响。Pegbovigrastim（PEG）在分娩前1周和分娩当天给药可以增强免疫功能并降低产后早期乳腺炎的发生率。氧脂是多不饱和脂肪酸（PUFA）的有效代谢产物，是炎症的重要介质。这项研究的目的是评估PEG在干燥前1周和干燥当天（D0）对血浆和牛奶中羟脂浓度的影响，从D0前7天到14后，以及随后泌乳的前14天的影响。我们假设促炎和抗炎的氧脂都会根据乳腺退化的开始而变化，并且pegbovigrastim会影响氧脂浓度。特别是那些与白细胞有关的。使用完全随机封闭设计将母牛纳入PEG处理组(n=10)或对照组(n=10;CON)。收集血样-7、-2、-1、0、1、2、4、7、14天(相对于干掉)和产卵后5、10和14天。通过超高效质谱和液相色谱串联四极杆质谱分析牛奶和血浆中的PUFA和羟脂，分别。总的来说,在牛奶和血浆中测量了30种脂质介质。重复测量分析显示，牛奶8-异-酮-15-前列腺素E2，前列腺素F2α的时间处理存在显着相互作用，血浆8,12-异前列腺素FαVI，11-羟基二十碳四烯酸，和12-羟基十七烯酸。在乳腺退化早期和产后早期，大多数牛奶PUFA和羟脂存在显着差异。这项研究表明，在早期退化过程中，牛奶分泌物和血浆中的脂质含量会发生变化，进一步的研究可能会阐明多个复杂的过程，并揭示优化乳腺退化的目标。
