Unscheduled DNA synthesis in human lymphocytes treated with cigarette smoke condensate and its semivolatile fraction.

Abstract

A cigarette smoke condensate (CSC) and the semivolatile fraction (SVF) from the CSC were tested for their ability to induce unscheduled DNA synthesis (UDS) in human lymphocytes. Exposed cells were incubated with tritiated thymidine and the UDS was determined by liquid scintillation counting of precipitated DNA. The tests were performed with and without metabolic activation by liver fraction (S9) from rats induced with Aroclor 1254. No UDS activity was detected, neither for the CSC nor for the SVF. Two control substances, benzo(a)pyrene and methyl methanesulfonate, increased the UDS activity in tests with and without metabolic activation, respectively. The scintillometric method used for detection of UDS was not sufficiently sensitive to be used as a tool for genetic risk assessment of CSC fractions.