Effects Of Hydrolysed Casein And Formula Milk On The Proliferation And Functional Maturation Of Calf Intestinal Epithelial Cells In Vitro

To find out the effects of milk-borne growth factors on gastrointestinal development, studies were conducted to examine the effects of the pepsinized casein(PC), trypsinized casein(TC), pepsinized formula milk(PFM) and trypsinized formula milk(TFM) on the proliferation, the glucose absorption and the enzyme activities of epithelium in small intestine of calves. Results showed that PC and TC reduced the rate of epithelia proliferation, facilitated the absorption of glucose by cells and increased the activity of Na+-K+-ATPase (P<0.05). But they have no impact on the activity of alkaline phosphatase (P>0.05). The activity of lactase was the highest when treated with casein that had been pepsinized or trypsinized for 60 minutes. In addition, both PFM and TFM significantly increased the rate of epithelia proliferation (P<0.01), the absorption of glucose (P<0.01)and the activity of lactase, with the exception of the formula milk that had been trypsinized for more than 60 minutes, which had the same effect on epitheliumproliferation as untreated formula milk. These results suggested that the active peptides can be released from casein and formula milk treated appropriately by enzymes, and enzyme treated casein as well as enzyme-treated formula milk can stimulate epithelium proliferation and the development of epithelium function in vito. The biological effects and the mechanism of molecular biology of the enzyme-treated casein and formula milk should be studied further.