The role of EGF,TGF-beta on developing gastrointestinal tract in artifically-rearing rats.

EGF、TGF-β对人工饲养大鼠胃肠道发育的作用。

• 批准号: 08680028
• 负责人: SHINOHARA Hisae
• 金额: $ 1.6万
• 依托单位: Miyazaki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08680028/
• 关键词: EGF; EMA; artificially-rearing; gastric emptying; intestinal motility; EMA(Evaporated Milk; Albumin)

Epidermal growth factor (EGF) is present in milk from various species. Rat milk contains 35-40 ng/ml of EGF.In contrast, EGF is absent in infant formulas. To clarify the hypothesis that milk-borne EGF plays an important role in the neonatal development of the gastrointestinal tract, suckling rats were fed either new rat milk substitute, Evaporated Milk Albumin (EMA) free of growth factors or EMA supplemented with EGF (100 ng/ml) for 4 day or for 8 days, utilizing an artificial ly-rearing technique.The results from our studies showed that in EMA-EGF(+) feeding rats, body weight gain and tail length were not significantly difference from EMA-EGF(-) feeding rats for 4 days or 8 days study period. For 4days feeding study, organ weights of stomach and the small intestine, content of protein and DNA were similar between two groups. Rats fed EMA-EGF(-) diet had markedly decreased serum EGF levels and intestinal EGF content. Results from measurements of gastric emptying and intestinal transit have shown that milk-borne EGF bad no effect on gastrointestinal motility. These results are agreement with our previous observation that short term orogastrically administered EGF has no immediate effect on intestinal motility (Shinohara data). Moreover the subcutaneous administration of EGF was accompanied by an immediate increase in serum EGF levels These results indicate that the EGF in vivo effects on gastrointestinal motility is regulated predominantly by parenteral administration of EGF.Eternal administration of EGF did not affect on sucrase specific activity, levels of sucrase-isomaltase mRNA and lactase-phlorizin mRNA.From present study we could not get dear results from animal fed EMA with TGF-beta, future studies are planned to address the physiological role of milk-borne TGF-beta on developing gastrointestinal tract function.

表皮生长因子（EGF）存在于不同物种的乳汁中。大鼠奶中含有35-40 ng/ml的EGF。相比之下，婴儿配方奶粉中不含EGF。为了阐明乳源性EGF在新生儿胃肠道发育中起重要作用的假设，哺乳大鼠喂养新的大鼠代乳品，不含生长因子的蒸发乳白蛋白（EMA）或补充有EGF的EMA（100 ng/ml）连续喂养4天或8天，结果表明，在EMA-EGF（+）喂养的大鼠中，在4天或8天的研究期间，EMA-EGF（-）喂养大鼠的体重增加和尾长没有显著差异。在4d的饲养试验中，两组的胃、小肠重量、蛋白质和DNA含量无显著差异。EMA-EGF（-）饲料喂养的大鼠血清EGF水平和肠EGF含量显著降低。胃排空和小肠传输的测量结果表明，乳源性EGF对胃肠动力没有影响。这些结果与我们先前的观察一致，即短期口腔胃施用EGF对肠运动没有立即作用（Shinohara数据）。这些结果表明EGF对胃肠运动的体内作用主要是通过肠外给药来调节的，EGF的长期给药不影响蔗糖酶的比活性，蔗糖酶-异麦芽糖酶mRNA和乳糖酶-根皮苷mRNA的水平。从目前的研究中，我们不能得到明确的结果，从动物饲养EMA与TGF-β，未来的研究计划解决乳源性TGF-β对发展胃肠道功能的生理作用。