Radioactive (I131-labeled) triolein has proved useful in the differential diagnosis of diarrhea, pancreatic disease, and malabsorption syndromes.1 Its absorption by the intestine, and appearance in the blood, depends on pancreatic lipase which splits fatty acids from triglyceride; absorption, and blood levels, are therefore low in individuals with pancreatic insufficiency, but may also be low in nonspecific malabsorption syndromes.
Absorption of I131-triolein has been quantified in three ways—by measuring blood levels for several hours,1 by stool,2 or by urine collections.3 In this laboratory, the standard method is measurement of radioactivity in whole blood specimens obtained two, four, and six hours after the patient swallows the I131-triolein capsule. Normally, a peak level of 6% to 15% in the total blood volume (estimated by weight) is found. Patients with severe chronic pancreatitis may have as little as 0.5% to 2%. In only one person have we failed to find any radioactivity at all
LOWENSTEIN JM. Bedside Prospecting With a Geiger Counter: An Unusual Case of Malabsorption. Arch Intern Med. 1963;112(2):164. doi:10.1001/archinte.1963.03860020062004
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