title: Flow cytometric analysis of the toxicity of nitrofen in cultured keratinocytes.
abstract: Lactate dehydrogenase (LDH) release test, 3H-thymidine (3H-TdR) and 3H-leucine (3H-Leu) incorporation tests and flow cytometric analysis (FCM) of cell cycle were employed 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 3H-Leu incorporation were found even at 0.01 mmol/L, and increased with the exposure dose. Cell cycle was analyzed from the DNA- histogram with propidium iodide 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 above 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.
authors.affiliation: Laboratory of Skin Physiology and Toxicology, School of Public Health, Shanghai Medical University, China.
authors.forename: L
authors.initials: L
authors.lastname: Yin
authors.forename: X P
authors.initials: XP
authors.lastname: Jin
authors.forename: X Z
authors.initials: XZ
authors.lastname: Yu
authors.forename: H F
authors.initials: HF
authors.lastname: Lin
mesh_terms: D000818:Animals; D002453:Cell Cycle; D002478:Cells, Cultured; D004249:DNA Damage / Q000187:drug effects*; D005434:Flow Cytometry; D006540:Herbicides / Q000633:toxicity*; D015603:Keratinocytes / Q000187:drug effects* / Q000502:physiology; D007770:L-Lactate Dehydrogenase / Q000187:drug effects / Q000378:metabolism*; D007930:Leucine / Q000378:metabolism; D010647:Phenyl Ethers / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D013936:Thymidine / Q000378:metabolism; D014316:Tritium
chemical_list: D006540:Herbicides; D010647:Phenyl Ethers; D014316:Tritium; D007770:L-Lactate Dehydrogenase; D007930:Leucine; C007350:nitrofen; D013936:Thymidine