title: Evaluation of ileal function using 23-selena-25-homotaurocholate, a-gamma-labeled conjugated bile acid. Initial clinical assessment.
abstract: 23-Selena-25-homotaurocholate is a synthetic bile acid labeled with a gamma-ray-emitting radioisotope 75Se. It is readily measured using external detectors and is thus suitable for whole-body counting. Whole-body retention was measured at 0, 4, and 7 days after oral administration to normal controls and to patients with disease of the small intestine, colon, or ileocecal region. Whole-body retention of less than 25% of the administered radioactivity within 4 days is definitely abnormal, but there was overlap between normal and abnormal groups at this time. At 7 days, whole-body retention less than 12% is abnormal and greater than 19% is normal. Between these limits, values may represent minimal ileal dysfunction not demonstrable by older techniques. Excretion of 23-selena-25-homotaurocholate follows a biexponential curve. The faster component has a half-life similar to that of natural bile acid. It is uncertain whether the slower component represents a hitherto unrecognized slowly turning over pool of bile acid or is a metabolic product of 23-selena-25-homotaurocholate not yet identified in vitro. There is a significant relationship between the whole-body retention of 23-selena-25-homotaurocholate and total fecal and primary bile acids. 23-selena-25-homotaurocholate is simple and acceptable for investigating ileal function.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003108:Colonic Diseases / Q000000981:diagnostic imaging; D003424:Crohn Disease / Q000000981:diagnostic imaging; D003967:Diarrhea / Q000000981:diagnostic imaging; D005260:Female; D006207:Half-Life; D006801:Humans; D007077:Ileal Diseases / Q000000981:diagnostic imaging*; D007082:Ileum / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011868:Radioisotopes; D011877:Radionuclide Imaging; D012643:Selenium; D013656:Taurocholic Acid / Q000031:analogs & derivatives*
chemical_list: D011868:Radioisotopes; D013656:Taurocholic Acid; C033638:23-seleno-25-homotaurocholic acid; D012643:Selenium