Cutler L S, Mooradian B A
J Dent Res. 1987 Oct;66(10):1559-62. doi: 10.1177/00220345870660100901.
This study utilized electron microscopy and enzyme histochemistry to examine the morphological steps associated with the formation of a lumen in the end-buds of the embryonic rat submandibular gland. Lumen formation involved the development of junctional complexes by the central cells of the end-buds late on the 16th day of gestation. These junctional complexes established the apical domains of the presecretory cells, and cytofilament aggregates were observed beneath the presumptive luminal plasma membranes. This central area of the end-buds showed strong myosin ATPase activity, presumably associated with the cytofilaments. On the 17th day of gestation, small lumina appeared at the sites delineated by the junctional complexes. The myosin ATPase activity appeared to surround the newly opened lumina. By the 18th day of gestation, microvilli were seen projecting into the lumina, and secretory granules were often visible in the apical cytoplasm near the luminal plasma membranes of the early secretory cells. Myosin ATPase activity was greatly reduced once the lumina had formed.
本研究利用电子显微镜和酶组织化学技术，检查与胚胎大鼠下颌下腺终末芽管腔形成相关的形态学步骤。管腔形成涉及妊娠第16日晚期终末芽中央细胞连接复合体的发育。这些连接复合体确立了分泌前细胞的顶端区域，并且在假定的管腔质膜下方观察到细胞丝聚集。终末芽的这个中央区域显示出强烈的肌球蛋白ATP酶活性，推测与细胞丝有关。在妊娠第17日，在由连接复合体划定的部位出现小的管腔。肌球蛋白ATP酶活性似乎围绕着新开放的管腔。到妊娠第18日，可见微绒毛突入管腔，并且在早期分泌细胞管腔质膜附近的顶端细胞质中常常可见分泌颗粒。一旦管腔形成，肌球蛋白ATP酶活性就大大降低。
