Abstract：
BACKGROUND: Milk production is under the influence of autocrine control such that the rate of milk synthesis decreases as the breast fills with milk. Effective elimination of milk from the alveoli via the milk ejection reflex will therefore result in increased milk synthesis. It has been assumed that milk ejection occurs in all alveoli simultaneously; however, animal studies have indicated that full alveoli eject milk sooner than less full alveoli, suggesting heterogeneous emptying of the mammary gland.
OBJECTIVE: The aim of this study was to determine whether milk ejection occurs asynchronously in the human lactating breast.
METHODS: Retrospective analysis of videos made of ultrasound monitoring of milk ducts during pumping. Six video clips (4 women) of ultrasound monitored milk ejections showed obvious differences in the timing of milk flow between different main milk ducts. Duct diameter was simultaneously measured every second in 2 different ducts that drained 2 separate lobes of the breast.
RESULTS: For 5 of 6 ultrasound duct monitoring sessions, both duct dilation and visualization of milk flow in the 2 separate main milk ducts differed by 2 to 8 seconds. For the remaining woman, milk was observed to eject from 1 part of the lobe, and when not removed, it flowed in a retrograde fashion into a different part of the lobe.
CONCLUSIONS: Asynchrony of milk ejection occurs in the human lactating breast, suggesting that the timing of myoepithelial cell response differs, resulting in heterogeneous emptying of the gland.
OBJECTIVE: The aim of this study was to determine whether milk ejection occurs asynchronously in the human lactating breast.
METHODS: Retrospective analysis of videos made of ultrasound monitoring of milk ducts during pumping. Six video clips (4 women) of ultrasound monitored milk ejections showed obvious differences in the timing of milk flow between different main milk ducts. Duct diameter was simultaneously measured every second in 2 different ducts that drained 2 separate lobes of the breast.
RESULTS: For 5 of 6 ultrasound duct monitoring sessions, both duct dilation and visualization of milk flow in the 2 separate main milk ducts differed by 2 to 8 seconds. For the remaining woman, milk was observed to eject from 1 part of the lobe, and when not removed, it flowed in a retrograde fashion into a different part of the lobe.
CONCLUSIONS: Asynchrony of milk ejection occurs in the human lactating breast, suggesting that the timing of myoepithelial cell response differs, resulting in heterogeneous emptying of the gland.
摘要：
背景：牛奶的生产受到自分泌控制的影响，因此随着乳房充满牛奶，牛奶合成的速率降低。因此,通过排奶反射从肺泡中有效地消除牛奶将导致牛奶合成增加。据推测，在所有肺泡中同时发生牛奶喷射；然而，动物研究表明，完整的肺泡比不太完整的肺泡更快地排出牛奶，提示乳腺异型排空。
目的：本研究的目的是确定人类泌乳过程中是否异步发生排乳。
方法：回顾性分析抽吸过程中超声监测乳导管的视频。超声监测的六个视频剪辑（4名女性）牛奶喷射显示，不同主乳导管之间的牛奶流动时间存在明显差异。在排出乳房的2个单独的叶的2个不同的导管中每秒同时测量导管直径。
结果：对于6次超声导管监测会话中的5次，导管扩张和2个独立的主乳管中的乳流可视化相差2至8秒。对于剩下的女人，观察到牛奶从叶的一部分喷出，当不删除时，它以逆行的方式流入肺叶的不同部分。
结论：在人类泌乳的乳房中发生排乳的不同步性，这表明肌上皮细胞反应的时机不同，导致腺体的异质排空。
目的：本研究的目的是确定人类泌乳过程中是否异步发生排乳。
方法：回顾性分析抽吸过程中超声监测乳导管的视频。超声监测的六个视频剪辑（4名女性）牛奶喷射显示，不同主乳导管之间的牛奶流动时间存在明显差异。在排出乳房的2个单独的叶的2个不同的导管中每秒同时测量导管直径。
结果：对于6次超声导管监测会话中的5次，导管扩张和2个独立的主乳管中的乳流可视化相差2至8秒。对于剩下的女人，观察到牛奶从叶的一部分喷出，当不删除时，它以逆行的方式流入肺叶的不同部分。
结论：在人类泌乳的乳房中发生排乳的不同步性，这表明肌上皮细胞反应的时机不同，导致腺体的异质排空。
