[The effect of the environment on the repair of DNA damage in human lymphocytes].

The dependence of UV-induced unscheduled DNA synthesis (UDS) in the unstimulated lymphocytes of human peripheral blood on the ionic strength (mu) of the culture medium has been shown. In the level of mu lower or higher than the physiological (mu ph) one, UDS significantly decreases. The effect of modification of mu due to the changes of ionic strength is absent in the lymphocytes of the classic form of xeroderma pigmentosum. The phenomenon may become useful in the development of a new test for revealing cells with a genetically or physiologically changed system of UV-induced DNA repair. The mechanisms of investigated phenomenon, particularly their dependence on the structure of chromatin, as well as the influence of ionic strength on binding of the repair enzymes with DNA are discussed.