title: Chi-square analysis of the reduction of ATP levels in L-02 hepatocytes by hexavalent chromium.
abstract: This study explored the reduction of adenosine triphosphate (ATP) levels in L-02 hepatocytes by hexavalent chromium (Cr(VI)) using chi-square analysis. Cells were treated with 2, 4, 8, 16, or 32 μM Cr(VI) for 12, 24, or 36 h. Methyl thiazolyl tetrazolium (MTT) experiments and measurements of intracellular ATP levels were performed by spectrophotometry or bioluminescence assays following Cr(VI) treatment. The chi-square test was used to determine the difference between cell survival rate and ATP levels. For the chi-square analysis, the results of the MTT or ATP experiments were transformed into a relative ratio with respect to the control (%). The relative ATP levels increased at 12 h, decreased at 24 h, and increased slightly again at 36 h following 4, 8, 16, 32 μM Cr(VI) treatment, corresponding to a "V-shaped" curve. Furthermore, the results of the chi-square analysis demonstrated a significant difference of the ATP level in the 32-μM Cr(VI) group (P < 0.05). The results suggest that the chi-square test can be applied to analyze the interference effects of Cr(VI) on ATP levels in L-02 hepatocytes. The decreased ATP levels at 24 h indicated disruption of mitochondrial energy metabolism and the slight increase of ATP levels at 36 h indicated partial recovery of mitochondrial function or activated glycolysis in L-02 hepatocytes.
authors.affiliation: School of Public Health, Central South University, Changsha Hunan, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yuan
authors.forename: Li
authors.initials: L
authors.lastname: Peng
authors.forename: Hu
authors.initials: H
authors.lastname: Gong-Hua
authors.forename: Dai
authors.initials: D
authors.lastname: Lu
authors.forename: Zhong
authors.initials: Z
authors.lastname: Xia-Li
authors.forename: Zhou
authors.initials: Z
authors.lastname: Yu
authors.forename: Zhong
authors.initials: Z
authors.lastname: Cai-Gao
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D002274:Carcinogens, Environmental / Q000633:toxicity*; D018929:Cell Culture Techniques; D002470:Cell Survival / Q000187:drug effects; D016009:Chi-Square Distribution; D002681:China; D002857:Chromium / Q000633:toxicity*; D004396:Coloring Agents; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D008930:Mitochondria, Liver / Q000378:metabolism; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D002274:Carcinogens, Environmental; D004396:Coloring Agents; D013778:Tetrazolium Salts; D013844:Thiazoles; D002857:Chromium; C074702:chromium hexavalent ion; D000255:Adenosine Triphosphate; C022616:thiazolyl blue