[Radio-adaptive response in repair-defective cells from patients with homocystinuria].

Two lines of fibroblasts isolated by skin biopsy from patients with homocystinuria were characterized as repair-defective cells. Preirradiation 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 used as damaging agents. The method for detection of DNA breaks by means of hydroxyapatite column chromatography of cell lysates and the method of determining sister chromatid exchanges (SCE) were used.