title: [Study on the adaptive reaction of low dose hydroquinone inducement in human embryo lung fibroblasts cells].
abstract: OBJECTIVE
  To study the adaptive reaction and its possible mechanisms in eukaryotic cells, the oxidize of adaptive mode was established by studying the dose-effect relation of inducing the adaptive reaction.
  
  
  METHODS
  Human embryo lung fibroblasts (HLF) were attacked 1 hour by 80.0 micromol/L concentration respectively after using a different concentration HQ to pretreat the 12 hours. The adaptive reaction of a low concentration HQ inducement was observed by combining the micronucleus test, the comet test and the cell cycle change.
  
  
  RESULTS
  The results showed that, in cellular viability, HLF induced by pretreated with HQ at 0.001 micromol/L and 0.0 micromol/L appeared to be tolerated when retreated by the following 80.0 micromol/L concentration of HQ. Compared with control respectively, the micronucleus rate and abnormal nuclei rate increased obviously by pretreatment with HQ concentration from 0.5 micromol/L to 80 micromol/L in HLF. Phenomena of cells with tails appeared, tail length and percentage of cells with tails increased significantly in HLF (P < 0.01). From 0.1 micromol/L pretreatment dose on, proportion of DNA lesion cells belonged to three and four grade increase gradually by the dose increasing. G2 phase arrest and cell numbers decreasing in G1. When compared with only high dose attack respectively, micronucleus rate, abnormal nuclei rate, tail length, percentage of cells with tails decreased significantly. proportion of severely damaged cells descended markedly by pretreatment with HQ from 0 micromol/L from 0.1 micromol/L in HLF (P < 0.05). It showed that there was a dose-related increase in the rate of micronucleus or abnormal nuclei, tail length and in percentage of cells with tails after pretreatment with HQ from 0 micromol/L to 80 micromol/L in HLF (P < 0.05).
  
  
  CONCLUSIONS
  HLF induced by pretreated with HQ at low concentration appeared to adaptive reaction when retreated by high concentration of HQ.
authors.affiliation: Department of Preventive Medicine, Guangdong Medical College, Zhanjiang 524023, China.
authors.forename: Huan-Wen
authors.initials: HW
authors.lastname: Tang
authors.forename: Hai-Rong
authors.initials: HR
authors.lastname: Liang
authors.forename: Zhi-Xiong
authors.initials: ZX
authors.lastname: Zhuang
mesh_terms: D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000166:cytology*; D006801:Humans; D006873:Hydroquinones / Q000633:toxicity*; D008168:Lung / Q000166:cytology* / Q000196:embryology; D015162:Micronucleus Tests
chemical_list: D006873:Hydroquinones