[Effects of exposure time using preliminary concentrations on the mutagenic effect of the basic action of one-center and dual-center mutagens].

The effect of exposition with pretreatment for thiophosphamide and dipin of human lymphocytes at Go phase was investigated. There were used 5 low concentrations of mutagens: 2, 0, 2; 2.10(-2); 2.10(-3), 2.10(-4) mcg/ml with different exposure: 1/4 hr, 1/2 hr, 1 hr and 4 hr and high concentration of 20 mcg/ml by which cell have been treated. There was discovered the dependence of the "protective" concentration on the exposition: the increase of exposition of pretreatment induced the decrease of "protective" concentration and vice versa.