Fluorescent dyes

1-anilino-naphthalene sulfonate (ANS) and 1

6-diphenyl-1

3

5-hexatriene (DPH)

were used as probes to examine the effect of γ-irradiation on the rat erythrocyte membrane.

After irradiation of rat erythrocyte membrane in vitro

the fluorescence intensity of membrane-associated ANS decreased with the increase of irradiation dose (10-40 Gy).

Similar results were also observed in the experiment of irradiation in vivo as showed by the decrease of fluorescence intensity of DPH probe in the erythrocyte membrane as well as the increase of its polarization on the 1 st

3 rd

5 th day following whole body irradiation with 8.5 Gy.

Those results reflected the decrease of membrane fluidity which was suggested to be resulted from lipid peroxidation of polyunsaturated fatty acid in membrane induced by γ-irradiation in vitro and in vivo.