RADIOADAPTIVE RESPONSE IN REPAIR-DEFECTIV E CELLS FROM PATIENTS WITH HOMOCYSTINURIA

Two lines of fibroblasts isolated by skin biopsy from patients with ho mocystinuria were characterized as repair-defective cells. Preirradiat ion of these cells at low doses (0.1 Gy) and irradiation at high doses demonstrated their decreased ability to form radioadaptive response, in comparison with normal cells. Radioadaptive response did not differ from that of normal cells after chemical treatment with 4NQO and NG u sed as damaging agents. The method for detection of DNA breaks by mean s of hydroxyapatite column chromatography of cell lysates and the meth od of determining sister chromatid exchanges (SCE) were used.