Radiation damage to lymphocyte membrane. Changes of binding and fluorescent parameters of 1-anilino-8-naphthalene sulphonate.

The changes of binding and fluorescent parameters of 1-anilino-8-naphthalene sulphonate (ANS) bound to lymphocyte membrane after irradiation in vitro were investigated. No significant dose dependence was found for either fluorescence or its polarization within the dose range of 0.1 to 0.7 Gy from a gamma-neutron field 252Cf source. Marked changes were however found for parameters of ANS binding to membrane after irradiation. The number of binding sites decreased by about 60% and the dissociation constant K decreased by about 70% as compared to control values. The quantum yield of fluorescence also decreased compared with control value. The experimental findings were interpreted as suggesting structural changes in the lipid environment of the lymphocyte membrane caused by irradiation.