EFFECTS OF NUTRIENTS AND HORMONES ON TRANSCRIPTIONAL AND POSTTRANSCRIPTIONAL REGULATION OF FATTY-ACID SYNTHASE IN RAT-LIVER
EFFECTS OF NUTRIENTS AND HORMONES ON TRANSCRIPTIONAL AND POSTTRANSCRIPTIONAL REGULATION OF FATTY-ACID SYNTHASE IN RAT-LIVER
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DOI：
10.1111/j.1432-1033.1990.tb15592.x
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发表时间：
1990-06-20
期刊：
影响因子：
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通讯作者：
TANAKA, T
中科院分区：
文献类型：
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作者：
KATSURADA, A;IRITANI, N;TANAKA, T
通过cDNA克隆，研究了营养素和激素对大鼠肝脏脂肪酸合成酶转录和转录后调控的影响。当禁食大鼠喂食碳水化合物/蛋白质饮食时，即使在1小时内，转录率也大大增加。转录速率、mRNA浓度和酶诱导分别在4 h、8-16 h和48 h达到最大值。虽然膳食碳水化合物比蛋白质更能提高每一水平，但碳水化合物和蛋白质都需要达到高水平。玉米油喂养显着降低转录速率。在糖尿病大鼠中，转录速率、mRNA浓度和酶诱导与正常相比非常低。然而，通过用胰岛素治疗糖尿病大鼠，转录速率在1小时内增加了5倍，在6小时内增加了15倍，在mRNA和酶水平大幅增加之前。另一方面，果糖喂养的三碘甲腺原氨酸治疗糖尿病大鼠大量增加的mRNA浓度，并在一定程度上增加了转录速率。因此，这表明，胰岛素主要刺激脂肪酸合成酶基因的转录，而三碘甲腺原氨酸和果糖主要增加mRNA的稳定性。
The effects of nutrients and hormones on trascriptional and post-transcriptional regulation of fatty acid synthase in rat liver were investigated following cDNA cloning. When fasted rats were fed a carbohydrate/protein diet, the transcriptional rate was greatly increased even in 1 h. The transcriptional rate, mRNA concentration and enzyme induction reached maximum level in 4 h, 8-16 h and 48 h, respectively. Although dietary carbohydrate increased each level more than protein did, both carbohydrate and protein were required to reach a high level. Corn oil feeding markedly decreased the transcriptional rate. In diabetic rats, the transcriptional rate, mRNA concentration and enzyme induction was very low in comparison with the normal. By treating the diabetic rats with insulin, however, the transcriptional rate was increased 5-fold in 1 h and 15-fold in 6 h, preceding a great increase in the mRNA and enzyme levels. On the other hand, fructose feeding of triiodothyronine treatment of diabetic rats abundantly increased the mRNA concentration and somewhat increased the transcriptional rate. Thus, it is suggested that insulin mainly stimulates the transcription of the fatty acid synthase gene, whereas triiodothyronine and fructose mainly increased the mRNA stability.