FIGURE 4.

Induction of DNA fragmentation in BY-2 cells exposed to lead. C, BY-2 cells cultured on LS medium – the control variant; MEL, BY-2 cells cultured on LS medium with 200 nM melatonin added from the beginning of the culture; Pb, BY-2 cells cultured on LS medium with 15 μM Pb²⁺ added on the 4th day of the culture and MEL + Pb, BY-2 cells cultured on LS medium with melatonin added from the start of the culture and with Pb²⁺ added on the 4th day of culture. DNA was obtained from the cells: 4, on the 4th day – 4 h after lead administration and 6, on the 6th day – 2 days after lead administration. DNA was analyzed by 2% agarose gel electrophoresis; M, molecular weight marker (pUC 18DNA Hae III digest).