Lactate dehydrogenase (LDH) release test, 3 H-thymidine (3 H-TdR) and 3 H-leucine (3 H-Leu) incoopration tests and flow cytometric analysis (FCM) of cell cycle were empoyed to elucidate cellular and molecular mechanis...Lactate dehydrogenase (LDH) release test, 3 H-thymidine (3 H-TdR) and 3 H-leucine (3 H-Leu) incoopration tests and flow cytometric analysis (FCM) of cell cycle were empoyed to elucidate cellular and molecular mechanism of nitrofen-induced toxicity in cultured keratinocytes.The results showed that cell morphologic damages were observed after exposure to 1.0 mmol/L and 10.0 mmol/L nitrofen. LDH release increased in a dose- and time-dependent manner. Depressions in 3H -TdR and 3 H-Leu incorpration were found even at 0.01 mmol/L, and increased with the exposure dose. Cell cycle was analyzed from the DNA- histogram with propidium iodde stain. The results showed that there was no pronounced alteration in cell cycle after cells exposed to 0.01 and 0.1 mmol/L nitrofen. At dose of 1.0 mmol/L, S phase cells increased 2 times of that of control. With the increase of dose, G2/M phase cells became to increase about 5 times of that of the control. At 1 .0 mmol/L, time course of cell cycle after exposure was observed. At the beginning of exposure, cells in S phase and G2/M phase were about 8 .7 % and 11 %. Following 24 h incubation with nitrofen, cells in S phase increased to 18.0% with almost no change in G2/M. 72 h after exposure, G2/M phase cells increased to 63 .3%. The forve results demonstrated that S phase and G2/M phase blockage in cultured keratinocytes after exposed to nitrofen seems of importance in the mechanism of nitrofen-induced toxicity.展开更多
文摘Lactate dehydrogenase (LDH) release test, 3 H-thymidine (3 H-TdR) and 3 H-leucine (3 H-Leu) incoopration tests and flow cytometric analysis (FCM) of cell cycle were empoyed to elucidate cellular and molecular mechanism of nitrofen-induced toxicity in cultured keratinocytes.The results showed that cell morphologic damages were observed after exposure to 1.0 mmol/L and 10.0 mmol/L nitrofen. LDH release increased in a dose- and time-dependent manner. Depressions in 3H -TdR and 3 H-Leu incorpration were found even at 0.01 mmol/L, and increased with the exposure dose. Cell cycle was analyzed from the DNA- histogram with propidium iodde stain. The results showed that there was no pronounced alteration in cell cycle after cells exposed to 0.01 and 0.1 mmol/L nitrofen. At dose of 1.0 mmol/L, S phase cells increased 2 times of that of control. With the increase of dose, G2/M phase cells became to increase about 5 times of that of the control. At 1 .0 mmol/L, time course of cell cycle after exposure was observed. At the beginning of exposure, cells in S phase and G2/M phase were about 8 .7 % and 11 %. Following 24 h incubation with nitrofen, cells in S phase increased to 18.0% with almost no change in G2/M. 72 h after exposure, G2/M phase cells increased to 63 .3%. The forve results demonstrated that S phase and G2/M phase blockage in cultured keratinocytes after exposed to nitrofen seems of importance in the mechanism of nitrofen-induced toxicity.
