Regulation of glucose-dependent insulinotropic peptide gene expression by a glucose meal.
Regulation of glucose-dependent insulinotropic peptide gene expression by a glucose meal.
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葡萄糖餐调节葡萄糖依赖性促胰岛素肽基因表达。
DOI：
10.1152/ajpgi.1994.266.5.g887
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Wolfe,MM
中科院分区：
文献类型：
--
作者：
Tseng,CC;Jarboe,LA;Wolfe,MM
葡萄糖依赖性促胰岛素肽（GIP）增强胰岛β细胞的胰岛素分泌。它的释放已被证明主要是在摄入碳水化合物和脂肪后。我们最近克隆了大鼠肠GIP cDNA，并在本研究中使用此cDNA作为探针，用于测量大鼠营养管理后的十二指肠GIP mRNA。将大鼠禁食过夜，之后允许它们饮水或10%葡萄糖。取十二指肠，用北方杂交法检测GIP mRNA，用放射免疫法检测十二指肠粘膜和血清GIP水平。响应于口服10%葡萄糖，十二指肠粘膜GIP mRNA浓度从2小时增加到4小时，并在4小时结束时检测到三倍的增加。血清和粘膜GIP浓度在60分钟开始升高，并且在4小时水平保持升高。在单独的研究中，进行了细胞核连续测定，以比较葡萄糖和水摄入对GIP基因转录的影响。然而，在饮用水的大鼠中没有检测到GIP基因转录的增加，而在葡萄糖喂养的大鼠中，转录速率翻了一番。肌动蛋白基因转录在两组中几乎相同，表明基因组特异性。这些研究的结果表明，十二指肠GIP基因表达的刺激在翻译前和翻译后水平的含葡萄糖的膳食。这些研究进一步表明，GIP从细胞储存颗粒中释放可能是口服葡萄糖摄入后血清GIP水平最初升高的原因。
Glucose-dependent insulinotropic peptide (GIP) enhances insulin secretion by pancreatic beta-islet cells. Its release has been demonstrated predominantly after the ingestion of carbohydrate and fat. We have recently cloned a rat intestinal GIP cDNA and in the present studies have used this cDNA as a probe for measuring rat duodenal GIP mRNA after nutrient administration. Rats were fasted overnight, after which they were permitted to drink water or 10% glucose. The duodenum was then removed, GIP mRNA was measured by Northern hybridization analysis, and duodenal mucosa and serum GIP levels were determined by radioimmunoassay. In response to oral 10% glucose, duodenal mucosal GIP mRNA concentrations increased from 2 to 4 h, and at the end of 4 h a threefold increase was detected. Serum and mucosal GIP concentrations increased earlier, starting at 60 min, and levels remained elevated at 4 h. In separate studies, nuclear run-on assays were performed to compare the effects of glucose and water ingestion on transcription of the GIP gene. Whereas no increase in GIP gene transcription was detected in rats ingesting water, the rate of transcription doubled in glucose-fed rats. Actin gene transcription was nearly identical in both groups, indicating genomic specificity. The results of these studies indicate that duodenal GIP gene expression is stimulated at both the pre- and posttranslational levels by glucose-containing meals. These studies further suggest that the release of GIP from cellular storage granules might account for the initial increase in serum GIP levels after oral glucose ingestion.