The relationship of putrescine incorporation to transferrin uptake by reticulocytes

We previously reported that putrescine incorporation occurred during transferrin uptake by rat reticulocytes (1). Both the putrescine incorporation and transferrin uptake were enhanced by the presence of Ca2+ and A23187. Furthermore, putrescine dose-dependently increased the transferrin uptake. Additionally, transglutaminase inhibitors partially blocked not only the putrescine incorporation but also the transferrin uptake.