DIFFERENTIAL-EFFECTS OF LIPID AND CARBOHYDRATE ON ENTEROCYTE LACTASE ACTIVITY IN NEWBORN PIGLETS

The influence of enteral feeding in the neonate on lactase-phlorizin h ydrolase activity in the small intestine has been determined in newbor n piglets fed a series of modified colostra, with a controlled metabol izable energy intake, during the first 31.5 h of life. Striking differ ences were observed between lactase specific activity in mucosal homog enates and enterocyte lactase activity along the villus axis; compared with newborns, the former decreased after feeding colostrum, whereas the latter increased significantly. When lipid was present in adequate amount, the increase in enterocyte lactase activity occurred when car bohydrate was present as either lactose or galactose. However, when th e lipid content of the diet was low, there was a specific effect of ca rbohydrate composition which was dependent on position along the villu s axis: in the lower villus, colostra high in lactose or glucose stimu lated an increase in lactase, but there was no such effect with a high galactose intake. It is concluded that colostrum increases enterocyte lactase activity during the first day of life, and that this is depen dent on both the nutrient composition of the diet and the position of the enterocytes along the villus.