Quantification of carcinoembryonic antigen-like activities in normal, human gastrointestinal secretions

The secretion of carcinoembryonic antigen-like (CEA-like) material into the gastrointestinal tract of 28 fasting normal men was quantified by using intestinal perfusion techniques. CEA-like material was recovered from all levels of the gastrointestinal tract. The highest secretory rate was in the colon (mean +/- SE, 2.41 +/- 2.0 mug/minute per colon), followed by pancreatobiliary secretion and pancreatic secretion. The secretory rate from the stomach, duodenum, jejunum, and ileum was less than 20 ng/minute. After perchloric acid extraction, the CEA-like material from the colon had the same chromatographic and radioimmunologic properties as [125I] CEA. These data suggest that the CEA-like material is normally secreted into the gastrointestinal tract and particularly into the colon.