Stimulation of protein absorption in the newborn piglet's intestine through the use of polyvalent cations

Abstract

SUMMARYThe transport of protein across the small intestine of the newborn pig was measuredin vitro. The transport of both bovine immune globulin and bovine plasma albumin showed a large variation between piglets. The polycations poly-ornithine, poly-arginine and poly-lysine stimulated both the transport of globulin and albumin. Protamine, histone and arginine were without effect on protein transport. Poly-ornithine became bound to albumin and to the piglet intestinal mucosa. The amount of poly-ornithine needed to stimulate albumin transport was of the same order as that needed to change the electrophoretic mobility of brush border membranes and some 30 times less than that needed to change the charge on the protein. It is concluded that polycations stimulate protein transport by a direct action on the brush border membrane of the pig intestinal mucosa.