Jin H S, Umemura S, Iwasaka T, Osamura R Y
Department of Pathology, Tokai University School of Medicine, Isehara, Japan.
Pathol Int. 2000 May;50(5):384-91. doi: 10.1046/j.1440-1827.2000.01064.x.
Hormone-induced alterations of myoepithelial cells in the mammary gland have not been fully investigated. The aim of the present study was to examine whether myoepithelial cells are altered in response to hormonal conditions. The immunohistochemical findings of smooth muscle actin for myoepithelial cells were studied during pregnancy, lactation and involution, and after estradiol dipropionate (ED) treatment (50, 500, 1000 microg/kg per week for 1-4 weeks) using a total of 71 Wistar female rats. Myoepithelial cells showed a stratified appearance around ducts during pregnancy, extended cytoplasmic processes with wider distance during lactation, and vacuolated cytoplasm after weaning. ED treatment (50-1000 microg/kg per week) for 1 week increased myoepithelial cells to a variable degree, achieving a level similar to that in pregnancy, but ED treatment for 4 weeks reduced them as the dose elevated. The present study showed that the myoepithelial cells became hyperplastic or hypertrophic by low-dose ED treatment within the physiological range, while weaning pups, and excess high-dose ED treatment beyond the physiological range or prolonged ED treatment induced reduction of the myoepithelial cells. Results indicate that myoepithelial cells themselves are also altered by hormonal conditions coordinating the mammary gland development.
激素诱导的乳腺肌上皮细胞变化尚未得到充分研究。本研究的目的是检验肌上皮细胞是否会因激素状况而发生改变。使用总共71只Wistar雌性大鼠，研究了妊娠、泌乳和 involution期间以及经二丙酸雌二醇（ED）治疗（每周50、500、1000微克/千克，持续1 - 4周）后，肌上皮细胞平滑肌肌动蛋白的免疫组化结果。肌上皮细胞在妊娠期间导管周围呈分层外观，泌乳期间细胞质突起延长且间距变宽，断奶后细胞质出现空泡。每周50 - 1000微克/千克的ED治疗1周可使肌上皮细胞不同程度增加，达到与妊娠时相似的水平，但4周的ED治疗会随着剂量升高而使其减少。本研究表明，在生理范围内低剂量ED治疗可使肌上皮细胞增生或肥大，而断奶幼崽、超出生理范围的过量高剂量ED治疗或延长的ED治疗会导致肌上皮细胞减少。结果表明，肌上皮细胞自身也会因协调乳腺发育的激素状况而发生改变。 （注：“ involution”此处可能有误，推测是“ involution”，意思是“退化、复旧”，这里结合语境可理解为断奶后的乳腺组织变化阶段，可根据实际情况修正）
