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

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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.