The influence of dose fractionation on radiation-induced haemolysis of human erythrocytes.

In this paper the radioresistance of human erythrocytes to radiation-induced haemolysis was studied by means of the split-dose technique. Human erythrocytes suspended in an isotonic Na-phosphatase buffer, pH 7.4 were exposed under air to gamma radiation. Erythrocytes were irradiated with a single dose of 2.7 kGy and with the same total dose split into two fractions with an interval between the subsequent exposures. It seems that postradiation processes initiated by the first radiation dose of definite magnitude can lead to an increase in the resistance of erythrocytes to haemolysis under the influence of subsequent dose. The maximal effect of the fractionation (50% decrease of haemolysis) was observed when the first fraction was equal to 0.3-0.4 kGy and the interval between exposures was equal to 3 h.