Quantitative and visualization studies of the transport of rat and bovine IgG and ferritin across the segments of the small intestine of the suckling rat.

Abstract

Quantitative and visualization studies have been made of the transport of [125I]rat IgG and [131I]ferritin across the duodenum, jejunum and ileum of the 14-day-old rat. The most active transport of both isotopes into the carcase occurs across the ileum, and although there is more breakdown of the proteins in the ileum, a great deal of this activity in the carcase is protein-bound. Ferritin is also transported in considerable amount across the duodenum. The selective ratio is slightly greater in the duodenum than in the ileum. These results are confirmed by visualization studies, which show ferritin entering and leaving both duodenal and ileal cells in quantity. Both markers are seen in the cytoplasm of both types of cell.