Changes in Oligosaccharides of Human Blood Cells Measured by Tritium- and FITC-labeled Lectins after in Vitro- and in Vivo-irradiation–lectin Binding as a ‘Biological Dosemeter’?

Summary

The lectin-binding system has been described previously as a biological dosi-meter, by revealing induced changes in oligosaccharides of the cell membrane. The measurements were performed by binding [³H]concanavalin A to blood cells. Our results on human blood cells irradiated in vitro with doses in the range 0·5–5 Gy indicate great difficulties in using radioactive labeled Con-A for an accurate quantitative analysis of radiation effects on cell membranes. It appears nearly impossible to differentiate between only a few damaged cells and the remaining undamaged cells.

Using fluorescein-labeled Con-A and wheat germ agglutinin, single-cell measurements of fluorescence intensity by flow cytometry revealed enhanced lectin-binding to platelets, lymphocytes and monocytes in the dose range 0·5–5 Gy after in vitro irradiation. But even by this method it was impossible to discriminate irradiations in either partial or whole-body irradiated patients. There were no significant or reproducible changes in the binding capacities of the blood-cell membranes of these patients. Therefore, the suitability of lectin binding as a ‘biological indicator’ for irradiation could not be confirmed.