[Selective effect of isoproterenol on radiosensitivity of cells associated with differences in beta-adrenoreceptor expression].

During x-ray irradiation of the joint cultures of cells 431 and cells B-82 of fibroblasts the antiradiation effect of isoproterenol manifests itself in regard to cells 431 only. As distinct from cells B-82, they bear beta-adrenoreceptors. The effect on them results in an increase in the cAMP intracellular content mediating the radioprotective effect. It has been noted that mammalian cells in malignancy often lose receptors to some hormones and biologically active substances which produce a radio-protective effect. It is assumed that the loss of receptors by tumor cells may be a factor opening up a new opportunity to the protection of normal cells from radiation injury in cancer radiotherapy.