[The absorption of cholecystographic contrast media, following intraduodenal application; reasons for improved absorption due to sodium bicarbonate (author's transl)].

Three different cholecystographic contrast media in six dilutions were administered through a duodenal tube to six groups of five patients each. Blood samples were obtained up to five hours following the introduction of the contrast, in order to determine serum iodine levels as a measure of contrast concentration in the blood. At one, two, four and five hours, radiographs of the abdomen were obtained in order to evaluate the biliary passages and non-absorbed contrast. 1. The known effect of increased absorption of a microcrystalline suspension of Iosumet acid caused by sodium bicarbonate was enhanced by intra-duodenal application. 2. Following intra-duodenal application, there was no definite effect on the blood level of Iosumet acid microsuspension due to the addition of sodium bicarbonate. Thus there was no evidence of increased absorption. It therefore seems that the effect of sodium bicarbonate is due to accelerated transport of the contrast medium from the stomach into the duodenum. 3. The micro-suspension is very rapidly dissolved in the duodenum. Ingestion of an acid solution does not improve absorption. 4. Micro-crystalline suspensions of iopodinic acid and particularly iopanic acid are absorbed relatively slowly and incompletely. The sodium salt of iopodinic acid is absorbed much better than the free acid.