Biosynthesis and transport of glycoproteins in the small intestinal epithelium of rats. I. Developmental change and effect of hypophysectomy.
Biosynthesis and transport of glycoproteins in the small intestinal epithelium of rats. I. Developmental change and effect of hypophysectomy.
复制标题
大鼠小肠上皮糖蛋白的生物合成和转运。
DOI：
10.1016/0012-1606(84)90159-3
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发表时间：
1984
影响因子：
2.7
通讯作者：
Moog,F
中科院分区：
文献类型：
--
作者：
Yeh,KY;Moog,F
用d-[~ 3 H]半乳糖、l-[~ 3 H]岩藻糖、ord-[~ 3 H]甘露糖经十二指肠腔内脉冲标记20分钟后，研究了6、24日龄完整大鼠和24日龄去垂体大鼠十二指肠吸收细胞糖蛋白的生物合成和胞内转运。放射自显影研究表明，糖的掺入显着增加，在6和24天之间的完整大鼠。当大鼠在6日龄时切除垂体，24日龄时肠上皮的dd-[3 H]半乳糖水平显著低于24日龄时完整大鼠的水平。垂体切除术也干扰了发育中[3 H]甘露糖掺入的增加，但不干扰l-[3 H]岩藻糖掺入。生化研究表明，注射-[3 H]半乳糖后20 min，24日龄完整大鼠肠道中无脂酸可沉淀糖蛋白的放射性分别比6日龄大鼠和24日龄垂体切除大鼠高129%和97%。新合成的半乳糖基化或岩藻糖基化的糖蛋白在所有动物组的细胞内运输的模式是相似的，标记的糖蛋白最初存在于高尔基体中，并通过滑面内质网运输到侧膜或刷状缘膜后60分钟内注射标记糖。然而，在d-[3 H]半乳糖注射后60-240分钟，6 - 24日龄的完整大鼠中迁移到刷状缘膜的标记糖蛋白的比例增加了约两倍。垂体切除干扰糖蛋白从顶端细胞质运输到刷状缘膜的发育增加。结果表明，在出生后发育过程中，单糖前体进入糖蛋白和新合成的半乳糖基化或岩藻糖基化糖蛋白转运到刷状缘膜的比例增加。发育变化至少部分受脑下垂体的调节。
The biosynthesis and intracellular transport of glycoproteins in duodenal absorptive cells of intact rats at 6 and 24 days and hypophysectomized rats at 24 days of age were studied after 20 min intralumenal pulse-labeling ofd-[3H]galactose,l-[3H]fucose, ord-[3H]mannose. Autoradiographic studies showed that the incorporation of sugars increased significantly in intact rats between 6 and 24 days. When rats were hypophysectomized at 6 days of age, the intestinal epithelium at 24 days incorporatedd-[3H]galactose at a level significantly lower than that of intact rats at 24 days. Hypophysectomy also interfered with the developmental increase ind-[3H]mannose, but not inl-[3H]fucose, incorporation. Biochemical study indicated that the radioactivity in the lipid-free acid-precipitable glycoproteins in the intestine of 24-day-old intact rats at 20 min afterd-[3H]galactose injection was 129% and 97% higher than that in 6-day-old rats and in 24-day-old hypophysectomized rats, respectively. The patterns of intracellular transport of newly synthesized galactosylated or fucosylated glycoproteins in all animal groups were similar; the labeled glycoproteins were initially present in the Golgi and were transported through the smooth endoplasmic reticulum to either the lateral membrane or the brush-border membrane within 60 min after the injection of labeled sugars. The proportion of labeled glycoproteins that migrated to the brush-border membrane, however, increased about twofold in the intact rats between 6 and 24 days of age at 60–240 min afterd-[3H]galactose injection. Hypophysectomy interfered with developmental increase in the transport of glycoproteins from the apical cytoplasm to the brush-border membrane. It was concluded that the incorporation of monosaccharide precursors into glycoproteins and the porportion of newly synthesized galactosylated or fucosylated glycoproteins transported to the brush-border membrane increase during postnatal development. The developmental changes are regulated, at least partially, by the pituitary gland.