Stern C D, MacKenzie D O
J Embryol Exp Morphol. 1983 Oct;77:73-98.
The sodium transport properties of chick epiblast during gastrulation were studied by various techniques. It was found that the epiblast is capable of unidirectional apical to basal sodium transport, in towards the underlying intraembryonic space. The Na-K-ATPase was localized by [3H]ouabain binding and autoradiography near the basal surfaces of the cells, and the number of pump sites was quantified. The transport rate of sodium was determined with 22Na. Electrophysiological studies on embryos at primitive streak stages showed a transepithelial potential of about +16 +/- 5 mV (basal side positive) which was sensitive to strophanthidin. Applying similar voltages but of reverse polarity to isolated sheets of epiblast caused a rapid reversal of some of their morphological polarity markers as well as some of their physiological functions. The relevance of these results to development is discussed.
利用多种技术研究了原肠胚形成期鸡胚外胚层的钠转运特性。发现外胚层能够进行从顶端到基底的单向钠转运，即朝着下方的胚内空间转运。通过[3H]哇巴因结合和放射自显影法将钠钾ATP酶定位在细胞基底表面附近，并对泵位点的数量进行了定量。用22Na测定了钠的转运速率。对原条期胚胎的电生理研究表明，跨上皮电位约为+16±5 mV（基底侧为正），该电位对毒毛花苷敏感。对分离的外胚层片施加相似但极性相反的电压会导致其一些形态极性标记以及一些生理功能迅速逆转。讨论了这些结果与发育的相关性。
