Cytological events involved in glycoprotein synthesis in cellular and syncytial trophoblast of human placenta. An electron microscope autoradiographic study of [3H]galactose incorporation
Cytological events involved in glycoprotein synthesis in cellular and syncytial trophoblast of human placenta. An electron microscope autoradiographic study of [3H]galactose incorporation
复制标题
细胞学事件涉及人胎盘细胞和合体滋养层糖蛋白的合成。
作者：
D M Nelson;A. C. Enders;B F King
采用电镜放射自显影技术，研究了D-[1-3H]半乳糖（[3H]gal）体外培养足月人胎盘绒毛细胞滋养层（细胞滋养层）和合胞滋养层中糖蛋白的合成。使用布莱克特和帕里（1973）的假设颗粒分析来分析自放射线照片。细胞生物学杂志。57:9-15)。本研究结果表明，[3H]gal在足月胎盘绒毛中的掺入主要局限于细胞滋养细胞。合胞滋养细胞对[3H]gal的利用率极低，产生的颗粒太少，无法进行定量的颗粒分析。这一结果与之前对[3H]亮氨酸结合的研究结果形成鲜明对比（Nelson， D. M.， A. C. Enders, and b.f. King, 1978）。在细胞滋养细胞内，粗内质网将大部分[3H]gal转化为糖蛋白。高尔基体是[3H]gal结合的另一个部位。在脉冲孵育期间并入细胞滋养层的绝大多数[3H]gal在整个实验过程中都保持在细胞内。放射自显像很少有氚化大分子分泌的证据。培养时间最长的细胞滋养细胞（4h +）显示，高尔基复合体和基质中有大量的氚化大分子，而粗内质网中没有。
Electron microscope autoradiography was used to study glycoprotein synthesis in cellular trophoblast (cytotrophoblast) and syncytial trophoblast of term human placental villi incubated in vitro with D-[1-3H]galactose ([3H]gal). Autoradiographs were analyzed using the hypothetical grain analysis of Blackett and Parry (1973. J. Cell Biol. 57:9-15). The results of this study indicated that [3H]gal incorporation into term placental villi was predominantly localized to cytotrophoblast. Utilization of [3H]gal by term syncytial trophoblast was extremely low and yielded too few grains for a quantitative grain analysis. This result is in striking contrast to that found in the preceding study of [3H]leucine incorporation (Nelson, D. M., A. C. Enders, and B. F. King. 1978). Within cytotrophoblast, the rough endoplasmic reticulum incorporated the most [3H]gal into glycoprotein. The Golgi apparatus was another site of [3H]gal incorporation. The vast majority of the [3H]gal incorporated into cytotrophoblast during the pulse incubation remained intracellular through the duration of the experiment. There was little autoradiographic evidence for secretion of tritiated macromolecules. Cytotrophoblast incubated for the longest time period studied (4 h+) showed a substantial concentration of tritiated macromolecules in the Golgi complex and in the ground plasm but not in the rough endoplasmic reticulum.