Welsch U, Singh S, Stemberger B H, Buchheim W, Patton S
Cell Tissue Res. 1983;230(3):527-41. doi: 10.1007/BF00216199.
The plant lectin, concanavalin A (Con A) suppresses milk secretion when infused into the mammary gland or when incubated with lactating tissue in vitro. Toward defining its mode of action, we infused Con A into rat and goat mammary glands via the teats and observed effects on lactating cells. Lectin dosages were 2 and 25 mg per gland for rats and goat, respectively. Tissue samples were taken 1 and 3 h post infusion for rats and at 24 h for the goat. Control and Con A-treated tissues were observed by light microscopy and by both thin section and freeze fracture electron microscopy. In comparison to controls, Con A-treated tissues of both species exhibited alveoli with enlarged cells and relatively empty lumina; cells were distended with secretory vesicles and fat droplets. Apical plasma membranes of lectin-affected cells of the rat displayed a marked reduction in the number of microvilli, and exhibited an atypical branching and folded structure. Morphometry was employed to quantitate changes in cell and secretory product parameters in both rat and goat tissue. Microtubule numbers and distribution did not appear to be altered by Con A but considerable changes were noted in the arrangement of microfilaments associated with the secretory surface of lectin-treated epithelial cells. Various related ultrastructural changes and the role of Con A in perturbing the microfilament system are discussed.
植物凝集素伴刀豆球蛋白A（Con A）注入乳腺或与体外泌乳组织一起孵育时会抑制乳汁分泌。为了确定其作用方式，我们通过乳头将Con A注入大鼠和山羊的乳腺，并观察对泌乳细胞的影响。大鼠和山羊的凝集素剂量分别为每腺体2毫克和25毫克。大鼠在注入后1小时和3小时采集组织样本，山羊在24小时采集。通过光学显微镜以及超薄切片和冷冻蚀刻电子显微镜观察对照和Con A处理的组织。与对照相比，两种动物经Con A处理的组织均显示肺泡细胞肿大且管腔相对空虚；细胞内充满分泌小泡和脂肪滴。大鼠中受凝集素影响的细胞的顶端质膜微绒毛数量明显减少，并呈现出非典型的分支和折叠结构。采用形态计量学方法对大鼠和山羊组织中的细胞和分泌产物参数变化进行定量。微管的数量和分布似乎未受Con A影响，但在与凝集素处理的上皮细胞分泌表面相关的微丝排列上观察到了显著变化。本文讨论了各种相关的超微结构变化以及Con A在扰乱微丝系统中的作用。
