Rubidium Transport in X-irradiated Human Erythrocytes

Summary

Outflow of ⁸⁶Rb, a radioactive analogue of potassium, from human erythrocytes X-irradiated in vitro was studied with the following results. (1) The ⁸⁶Rb level in the supernatants of irradiated and control cell suspensions reflected mainly ⁸⁶Rb outflow and much less its active re-uptake. (2) The effect of irradiation on ⁸⁶Rb outflow was more pronounced at a low temperature (4°C) than at 37°C; the lowest dose of X-radiation exhibiting a significant effect on ⁸⁶Rb outflow at 4°C was 2·5 Gy. (3) K/Rb exchange did not seem to play an appreciable role in radiation-induced ⁸⁶Rb outflow. (4) Calcium and its accumulation in irradiated cells was not found to be the cause of the effect of radiation on ⁸⁶Rb outflow. (5) The effect of radiation on ⁸⁶Rb outflow was higher in low Na medium but it was not inhibited by bumetanide. Rb/Na counter- or co-transport do not therefore seem to be involved in radiation-induced Rb⁺ outflow.

• X-irradiation
• human erythrocytes
• Rb⁺ transport
• Ca²⁺ transport