Glut-1 expression and its response to hypoglycemia in the embryonic mouse heart.
Glut-1 expression and its response to hypoglycemia in the embryonic mouse heart.
复制标题
胚胎小鼠心脏中 Glut-1 的表达及其对低血糖的反应。
DOI：
10.1007/s004290050321
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Branch,S
中科院分区：
文献类型：
--
作者：
Smoak,IW;Branch,S
胚胎心脏在早期器官发生过程中依赖于葡萄糖。Glut-1在成人组织中的组成性葡萄糖摄取中起作用，并且是胚胎和胎儿组织中的主要葡萄糖转运蛋白。本研究的重点是在心脏中的Glut-1的表达，在正常器官形成过程中，使用免疫组化的Glut-1分布，蛋白质分析的Glut-1蛋白水平，和逆转录聚合酶链反应的Glut-1 mRNA水平。使用Glut抑制剂细胞松弛素B评价Glut在胚胎心脏对低血糖的葡萄糖摄取反应中的作用。还在体外低血糖暴露后评价心脏Glut-1表达。在正常胚胎心脏中，Glut-1水平在妊娠第9-10天最高，在妊娠第10.5天居中，在妊娠第11.5-13.5天最低。心脏Glut-1 mRNA水平在妊娠第9.5天和妊娠第13.5天之间也同样下降。细胞松弛素B在暴露于低血糖30分钟或6小时的心脏中产生葡萄糖摄取的剂量依赖性降低，这与Glut有关。Glut-1蛋白表达在妊娠第9.5天心脏中低血糖2或6小时后不变，但在12和24小时后增加。因此，Glut-1的表达在胚胎心脏中是突出的，并且与正常器官发生期间心脏葡萄糖需求的变化相关。Glut活性在急性低血糖时增加，Glut-1的表达在长期低血糖时增加。这些结果支持了Glut-1在正常心脏发生过程中以及在胚胎心脏低血糖反应中的重要性。
The embryonic heart depends on glucose during early organogenesis. Glut-1 functions in constitutive glucose uptake in adult tissues and is the predominant glucose transporter in embryonic and fetal tissues. This study focuses on Glut-1 expression in the heart during normal organogenesis using immunohistochemistry for Glut-1 distribution, Western analysis for Glut-1 protein levels, and reverse transcriptase polymerase chain reaction for Glut-1 mRNA levels. The role of Glut in glucose uptake response to hypoglycemia in the embryonic heart is evaluated using the Glut inhibitor cytochalasin B. Cardiac Glut-1 expression is also evaluated after in vitro hypoglycemic exposure. Glut-1 levels are highest on gestational days 9–10, intermediate on gestational day 10.5, and lowest on gestational days 11.5–13.5 in the normal embryonic heart. Cardiac Glut-1 mRNA levels similarly decline between gestational days 9.5 and gd 13.5. Cytochalasin B produces a dose-dependent decrease in glucose uptake in hearts exposed to hypoglycemia for 30 min or 6 h, implicating Glut in this response. Glut-1 protein expression is unchanged after 2 or 6 h but increased after 12 and 24 h of hypoglycemia in the gestational day 9.5 heart. Thus, Glut-1 expression is prominent in the embryonic heart and is correlated with changes in cardiac glucose requirements during normal organogenesis. Glut activity increases in response to acute hypoglycemia and the expression of Glut-1 increases in response to prolonged hypoglycemia. These results support the importance of Glut-1 during normal cardiogenesis and in response to hypoglycemia in the embryonic heart.