Effect of radiation on glucose absorption in the mouse jejunum in vivo

In an attempt to develop a clinical assay for intestinal damage, the relationship between radiation dose and glucose absorption in the jejunum has been investigated. Lightly anesthetised C3D2F1 mice had their upper abdomen irradiated. The intestine was exteriorized and a 10-cm segment of the jejunum was isolated and included in a closed circuit perfusion loop. An isotonic solution containing 2 mg/ml D-glucose was perfused in 2 h and the rate of glucose absorption calculated. The absorption decreased as a function of dose and time after irradiation with the most prominent reduction after 4-5 days, returning to normal within a week after irradiation. A dose-response relationship was found after single doses between 5 and 17.5 Gy. Split-dose recovery of approximately 7.5 Gy was found within 2-4 h. This absorption insufficiency was only found to be present acutely, and no late abnormalities were seen for times greater than 12 months after irradiation. The results correlated with other functional endpoints such as absorptive surface. This assay seems suitable to demonstrate (acute) functional intestinal radiation damage and has obvious clinical applicability.