In vitro absorption of gamma-globulin by neonatal intestinal epithelium of the pig.
1. An in vitro method, using fluorescent gamma-globulin and everted neonatal pig's intestinal slices, for the study of the active transport of large molecules is described.2. Uptake of gamma-globulin occurred within 15 min and required no exogenous substrates.3. In vitro absorption of gamma-globulin by intestinal epithelium was limited to the neonatal pig and 5-day-old mouse. No uptake was seen in intestines from a mature mouse, a pig with diarrhoea, a normal pig, a mature rabbit, a guinea-pig, a chick, and a chick embryo. Chick embryo yolk sac readily took up gamma-globulin.4. Rings of everted intestinal epithelium remained active (still absorbed gamma-globulin) after incubating for 4-6 hr in balanced salt solution (BSS).5. Uptake of gamma-globulin required oxygen and sodium and was reversibly inhibited by metabolic antagonists such as iodoacetate, arsenate, fluoride, 4,6-dinitro-varphi-cresol, phlorrhizin, anaerobiosis and cold. Under the conditions of the test, large colloidal molecules did not inhibit uptake of gamma-globulin.6. Similar results (although not as clear-cut) with metabolic inhibitors were obtained with preparations of chick embryo yolk sacs.7. Injuring mature pig's intestinal epithelium with surface-active agents did not produce non-specific absorption artifacts that resembled the specific absorption found in immature pig's intestinal epithelium.
D000818:Animals; D001152:Arsenicals / Q000494:pharmacology; D001693:Biological Transport, Active; D002642:Chick Embryo; D003080:Cold Temperature; D003408:Cresols / Q000494:pharmacology; D004848:Epithelium / Q000378:metabolism*; D006168:Guinea Pigs; D007408:Intestinal Absorption; D007461:Iodoacetates / Q000494:pharmacology; D051379:Mice; D010100:Oxygen / Q000494:pharmacology; D010695:Phlorhizin / Q000494:pharmacology; D011200:Poultry; D011817:Rabbits; D012964:Sodium / Q000494:pharmacology; D013552:Swine; D005719:gamma-Globulins / Q000378:metabolism*
D001152:Arsenicals; D003408:Cresols; D007461:Iodoacetates; D005719:gamma-Globulins; D012964:Sodium; D010695:Phlorhizin; D010100:Oxygen