Ames I H, Richman R A, Gordon G B, Toly B A, Benedict M R, Barcza M A
Scan Electron Microsc. 1985(Pt 3):1143-50.
In an attempt to understand the hormonal regulation of somatomedin secretion in the fetus, we have confirmed that epidermal growth factor (EGF) stimulates fetal rat hepatocytes in primary culture to secrete somatomedin in a time and a dose-dependent fashion. Transmission electron microscopy (TEM) revealed that the cultured cells had ultrastructural features consistent with those of fetal hepatocytes. Scanning electron microscopy (SEM) showed that cells grown in either Medium 199 or EGF supplemented Medium 199 formed cellular aggregates within 6 h. The surface features of cells in control and experimental cultures were indistinguishable up until 24 h after exposure to EGF. At this point in time, morphological differences between treatment groups were first apparent with SEM. In the presence of EGF, cellular aggregates were thicker, cells were more rounded in contour, and the number of microvilli and cytoplasmic excrescences (blebs) was greater than in control cultures. These differences were further accentuated at 48 h after exposure to the growth factor. Since the appearance of microvilli and blebs coincides with increasing production of somatomedin, they may represent morphological evidence of secretory activity.
为了了解胎儿中生长调节素分泌的激素调控机制，我们已经证实，表皮生长因子（EGF）能刺激原代培养的胎鼠肝细胞，使其以时间和剂量依赖的方式分泌生长调节素。透射电子显微镜（TEM）显示，培养的细胞具有与胎肝细胞一致的超微结构特征。扫描电子显微镜（SEM）表明，在199培养基或添加了EGF的199培养基中生长的细胞，在6小时内会形成细胞聚集体。在暴露于EGF后的24小时内，对照培养和实验培养中的细胞表面特征没有区别。此时，用SEM首次观察到处理组之间的形态差异。在EGF存在的情况下，细胞聚集体更厚，细胞轮廓更圆，微绒毛和细胞质突起（泡）的数量比对照培养中的更多。在暴露于生长因子48小时后，这些差异进一步加剧。由于微绒毛和泡的出现与生长调节素产量的增加同时发生，它们可能代表了分泌活动的形态学证据。
