Kinetic studies on IgG transport by the jejunum of the neonatal rat.
A 0.2-ml dose containing 500 micrograms labelled rat IgG saturated the receptor-mediated transport system of the enterocytes of the jejunum of the small intestine. At subsaturation dose levels very little intracellular digestion of IgG occurred--the intact transport system was primarily employed. The uptake of IgG by enterocytes, at doses above saturation, was assessed over periods up to 6 h. There was an initial phase of rapid intracellular digestion by the enterocytes, followed by a much longer period during which the receptor-mediated transport system discharged intact IgG into the vascular compartment. The observations are discussed in the light of recent evidence relating to the numbers of IgG receptors on jejunal enterocytes.
D000818:Animals; D000831:Animals, Newborn; D007074:Immunoglobulin G / Q000378:metabolism*; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000276:immunology; D007583:Jejunum / Q000276:immunology*; D007700:Kinetics; D051381:Rats; D011919:Rats, Inbred Strains; D017452:Receptors, IgG; D011971:Receptors, Immunologic / Q000378:metabolism
D007074:Immunoglobulin G; D017452:Receptors, IgG; D011971:Receptors, Immunologic