Zhang Feng, Xue Qin, Bai Ting, Wu Fan, Yan Shuhan
Medical College, 66479Nantong University, Nantong City, Jiangsu Province, China.
Biol Res Nurs. 2022 Jan;24(1):128-139. doi: 10.1177/10998004211050047. Epub 2021 Oct 31.
Postpartum fatigue is a common disorder worldwide and affects both physical and mental functioning. In breastfeeding women, Prolactin (PRL) is not only involved in immunoregulation, but also responsible for lactation. Prolactin levels in women with chronic fatigue are higher than normal, but a chronic fatigue state inhibits postpartum lactation in humans. This paper explored the inhibition mechanism of lactation by postpartum fatigue in rats. Postpartum fatigue models were built by forcing mother rats to stand in water and divided into 3-hour, 9-hour and 15-hour per day fatigue groups according to the underwater time. Mother rats and their offspring were reunited in a dry cage for 90 minutes every 3 hours for feeding. The expression of PRL, PRL receptor (PRLR), Janus Kinase 2 (JAK 2), and Signal transducers and activators of transcription 5 (STAT5) mRNA were analyzed and the microstructure of mammary gland were observed under light and electron microscopy. The expression of pituitary PRL mRNA and its downstream signaling pathway JAK2 and STAT5 mRNA were down-regulated in the severe postpartum fatigue rats. PRL mRNA responses were dose-related to duration of fatigue. The expression of PRLR mRNA increased. Postpartum fatigue led to functional degeneration of mammary gland. The breast lobules were shrunk and the number of alveoli were decreased. Few milk protein granules and fat droplets were observed in the cytoplasm under transmission electron microscope. Postpartum fatigue inhibits the lactation by down-regulating the expression of PRL and PRL-dependent signaling pathway in rats.
产后疲劳是一种全球范围内常见的病症，会影响身体和心理功能。在哺乳期女性中，催乳素（PRL）不仅参与免疫调节，还负责泌乳。慢性疲劳女性的催乳素水平高于正常水平，但慢性疲劳状态会抑制人类产后泌乳。本文探讨了大鼠产后疲劳对泌乳的抑制机制。通过强迫母鼠站在水中建立产后疲劳模型，并根据水下时间分为每天3小时、9小时和15小时的疲劳组。每3小时将母鼠及其后代放回干燥笼中90分钟进行哺乳。分析催乳素（PRL）、催乳素受体（PRLR）、Janus激酶2（JAK 2）和信号转导子与转录激活子5（STAT5）mRNA的表达，并在光学和电子显微镜下观察乳腺的微观结构。严重产后疲劳大鼠垂体PRL mRNA及其下游信号通路JAK2和STAT5 mRNA的表达下调。PRL mRNA反应与疲劳持续时间呈剂量相关。PRLR mRNA的表达增加。产后疲劳导致乳腺功能退化。乳腺小叶萎缩，腺泡数量减少。在透射电子显微镜下，细胞质中观察到很少的乳蛋白颗粒和脂肪滴。产后疲劳通过下调大鼠PRL及其依赖信号通路的表达来抑制泌乳。
