Regulation of the gene expression of glucokinase and L-type pyruvate kinase in primary cultures of rat hepatocytes by hormones and carbohydrates.
Regulation of the gene expression of glucokinase and L-type pyruvate kinase in primary cultures of rat hepatocytes by hormones and carbohydrates.
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激素和碳水化合物对大鼠肝细胞原代培养物中葡萄糖激酶和 L 型丙酮酸激酶基因表达的调节。
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
T. Tanaka
中科院分区：
文献类型：
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作者：
T. Matsuda;T. Noguchi;K. Yamada;M. Takenaka;T. Tanaka
在成年大鼠肝细胞的原代培养物中，研究了激素和碳水化合物对两种重要糖酵解酶（葡萄糖激酶和 L 型丙酮酸激酶）基因表达的调节。胰岛素导致肝细胞中两种酶的 mRNA 数量呈时间和剂量依赖性增加，尽管葡萄糖激酶对这种激素的反应比 L 型丙酮酸激酶更快。胰岛素诱导葡萄糖激酶mRNA不需要葡萄糖本身的存在，但L型同工酶的存在依赖于葡萄糖浓度。对于这种效果，果糖和甘油可以部分替代葡萄糖，但丙酮酸和2-脱氧葡萄糖（一种不可代谢的葡萄糖类似物）却不能。在存在果糖但不存在甘油的情况下胰岛素诱导的时间过程与存在葡萄糖的情况相似。在甘油存在下，mRNA以双相方式增加：第一次增加可能反映了正常肝脏中果糖和甘油的影响，在3小时后达到最大值，而第二次增加对应于葡萄糖存在下的增加。这些结果表明，胰岛素诱导的 L 型丙酮酸激酶 mRNA 增加需要一些葡萄糖代谢物。放线菌酮抑制胰岛素对这两种 mRNA 的作用，表明这两种情况都需要持续的蛋白质合成。添加蛋白激酶 C 抑制剂 1-(5-异喹啉磺酰基)-2-甲基哌嗪也能抑制胰岛素的作用。然而，单独使用佛波醇 12-肉豆蔻酸酯 13-乙酸酯并不能诱导这两种 mRNA。（摘要截断为 250 字）
The regulation of the gene expression of two important glycolytic enzymes, glucokinase and L-type pyruvate kinase, by hormones and carbohydrates was studied, in primary cultures of adult rat hepatocytes. Insulin caused time- and dose-dependent increases in the amounts of the mRNAs of the two enzymes in hepatocytes, although glucokinase responded to this hormone faster than L-type pyruvate kinase. The induction of glucokinase mRNA by insulin did not require the presence of glucose itself, but that of the L-type isozyme was dependent on the glucose concentration. For this effect, fructose and glycerol could partially substitute for glucose, but pyruvate and 2-deoxyglucose, a nonmetabolizable glucose analog, could not. The time course of insulin induction in the presence of fructose, but not of glycerol, was similar to that in the presence of glucose. In the presence of glycerol, the mRNA increased in a diphasic manner: the first increase, which probably reflected the effects of fructose and glycerol in normal liver, reached a maximum after 3 h, whereas the second increase corresponded to the increase in the presence of glucose. These results suggested that some metabolite of glucose was required for the insulin-induced increase in L-type pyruvate kinase mRNA. Cycloheximide inhibited the effects of insulin on the two mRNAs, suggesting that ongoing protein synthesis is required in both cases. The addition of 1-(5-isoquinolinesulfonyl)-2-methylpiperazine, an inhibitor of protein kinase C, also inhibited the effects of insulin. However, phorbol 12-myristate 13-acetate alone did not induce the two mRNAs.(ABSTRACT TRUNCATED AT 250 WORDS)