Dakshinamurti K, Li W
Department of Biochemistry and Molecular Biology, University of Manitoba, Winnipeg, Canada.
Mol Cell Biochem. 1994 Mar 30;132(2):127-32. doi: 10.1007/BF00926921.
Rat liver phosphoenolpyruvate carboxykinase (PEPCK) activity was followed over a time period of 5 h following administration of biotin to streptozotocin-induced diabetic rats. In parallel with the decrease in enzyme activity liver PEPCK mRNA decreased by 85% at 3 h after injection of biotin to diabetic rats. There was no significant change in the accumulation of kidney PEPCK mRNA. Parallel studies with insulin indicated that biotin had a regulatory effect similar to that of insulin on liver PEPCK mRNA. The administration of biotin did not change the insulin status of the diabetic rat indicating that biotin did not act via insulin. The transcriptional activity of the hepatic PEPCK gene, as measured by nuclear run-on assay, was decreased by 57% within 30 min of biotin administration. The results suggest that biotin regulates hepatic, but not renal, PEPCK mRNA concentration at the transcriptional level in diabetic rats.
给链脲佐菌素诱导的糖尿病大鼠注射生物素后，在5小时的时间段内监测大鼠肝脏磷酸烯醇丙酮酸羧激酶（PEPCK）的活性。与酶活性降低同时，给糖尿病大鼠注射生物素后3小时，肝脏PEPCK mRNA下降了85%。肾脏PEPCK mRNA的积累没有显著变化。与胰岛素的平行研究表明，生物素对肝脏PEPCK mRNA具有与胰岛素相似的调节作用。生物素的给药并未改变糖尿病大鼠的胰岛素状态，表明生物素并非通过胰岛素起作用。通过核转录分析测定，肝脏PEPCK基因的转录活性在生物素给药后30分钟内下降了57%。结果表明，生物素在转录水平上调节糖尿病大鼠肝脏而非肾脏的PEPCK mRNA浓度。
