EFFECT OF DIABETES AND FASTING ON GLUT-4 (MUSCLE FAT) GLUCOSE-TRANSPORTER EXPRESSION IN INSULIN-SENSITIVE TISSUES - HETEROGENEOUS RESPONSE IN HEART, RED AND WHITE MUSCLE
EFFECT OF DIABETES AND FASTING ON GLUT-4 (MUSCLE FAT) GLUCOSE-TRANSPORTER EXPRESSION IN INSULIN-SENSITIVE TISSUES - HETEROGENEOUS RESPONSE IN HEART, RED AND WHITE MUSCLE
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DOI：
10.1042/bj2820765
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发表时间：
1992-03-15
影响因子：
4.1
通讯作者：
ZORZANO, A
中科院分区：
文献类型：
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作者：
CAMPS, M;CASTELLO, A;ZORZANO, A
1.检测链脲佐菌素诱导的糖尿病大鼠和禁食48小时的大鼠心脏、红肌、白肌以及棕色和白色脂肪组织中GLUT-4葡萄糖转运体蛋白和mRNA的表达水平。2.与先前的数据一致，白色脂肪组织显示Glut-4mRNA和蛋白水平在糖尿病和禁食的反应中显著降低。类似地，在两种胰岛素分泌条件下，棕色脂肪组织中的GLUT-4mRNA和蛋白质显著减少。3.在对照条件下，心脏、红色和白色骨骼肌中GLUT-4蛋白含量的表达水平有很大差异。因此，心脏中的GLUT-4蛋白含量最高，与白肌相比，红色肌肉中的GLUT-4含量更高。尽管GLUT-4蛋白含量差异很大。GLUT-4mRNA在心脏和红色骨骼肌中的表达水平相同。4.在糖尿病和空腹状态下，心脏组织中GLUT-4mRNA的表达下降幅度大于GLUT-4蛋白的表达。相比之下，在糖尿病或禁食的情况下，红色肌肉中GLUT-4蛋白的下降幅度大于mRNA，事实上禁食时GLUT-4的mRNA含量并未检测到下降。另一方面，白色骨骼肌制剂在两种胰岛素分泌条件下都显示出Glut-4mRNA的显著增加，这要么伴随着糖尿病患者Glut-4蛋白的轻微下降，要么伴随着空腹没有变化。5.这些结果表明：(A)糖尿病和禁食对GLUT-4表达的影响几乎是相同的，并导致组织特异性的GLUT-4表达的变化；(B)白色脂肪组织、棕色脂肪组织和心脏对胰岛素缺乏的反应类似，其降低幅度大于GLUT-4蛋白；(C)红色和白色骨骼肌对胰岛素分泌条件的反应是不同的，其特征是GLUT-4mRNA/蛋白质比率增加。
1. GLUT-4 glucose-transporter protein and mRNA levels were assessed in heart, red muscle and white muscle, as well as in brown and white adipose tissue from 7-day streptozotocin-induced diabetic and 48 h-fasted rats. 2. In agreement with previous data, white adipose tissue showed a substantial decrease in GLUT-4 mRNA and protein levels in response to both diabetes and fasting. Similarly, GLUT-4 mRNA and protein markedly decreased in brown adipose tissue in both insulinopenic conditions. 3. Under control conditions, the level of expression of GLUT-4 protein content differed substantially in heart, red and white skeletal muscle. Thus GLUT-4 protein was maximal in heart, and red muscle had a greater GLUT-4 content compared with white muscle. In spite of the large differences in GLUT-4 protein content. GLUT-4 mRNA levels were equivalent in heart and red skeletal muscle. 4. In heart, GLUT-4 mRNA decreased to a greater extent than GLUT-4 protein in response to diabetes and fasting. In contrast, red muscle showed a greater decrease in GLUT-4 protein than in mRNA in response to diabetes or fasting, and in fact no decrease in GLUT-4 mRNA content was detectable in fasting. On the other hand, preparations of white skeletal muscle showed a substantial increase in GLUT-4 mRNA under both insulinopenic conditions, and that was concomitant to either a modest decrease in GLUT-4 protein in diabetes or to no change in fasting. 5. These results indicate that (a) the effects of diabetes and fasting are almost identical and lead to changes in GLUT-4 expression that are tissue-specific, (b) white adipose tissue, brown adipose tissue and heart respond similarly to insulin deficiency by decreasing GLUT-4 mRNA to a larger extent than GLUT-4 protein, and (c) red and white skeletal muscle respond to insulinopenic conditions in a heterogeneous manner which is characterized by enhanced GLUT-4 mRNA/protein ratios.