These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: [Stimulatory response to the oxidation of benzidine and other xenobiotics mediated by lipoxygenase in the presence of phenothiazines].
    Author: Hu JA, Wu Y, Kulkarni AP.
    Journal: Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi; 2004 Jun; 22(3):184-7. PubMed ID: 15256151.
    Abstract:
    OBJECTIVE: To test the possibility that certain efficient substrates for lipoxygenase (LOX) produce shuttle oxidants that stimulate the generation of reactive oxygen species from other chemicals. METHODS: Metabolic interactions were conducted in vitro between chlorpromazine (BZ) or other phenothiazines and benzidine or other xenobiotics mediated by soybean lipoxygenase (SLO) or purified human term placental lipoxygenase (HTPLO) in the presence of hydrogen peroxide, and the rates of xenobiotics oxidation were measured by spectroscopic analysis. RESULTS: Chlorpromazine cation radical (CPZ(*+)) generated by lipoxygenase triggered a rapid oxidation of benzidine to benzidine diimine cation. Under the experimental conditions used, the metabolic interaction resulted in a 42-fold greater stimulation than BZ alone in the rate of BZ oxidation. The magnitude of stimulation of benzidine oxidation exhibited a dependence on the pH of the reaction medium, amount of the enzyme, and concentration of chlorpromazine, BZ, and hydrogen peroxide. A number of other phenothiazines were also found to stimulate BZ oxidation, albeit to a lesser degree. Chlorpromazine cation radical stimulated the oxidation of all six other xenobiotics tested. The highest stimulation (94-fold) was noted in the oxidation of tetramethyl phenylenediamine to Wursters blue radical, while the lowest stimulatory response (2-fold) was observed in guaiacol. Preliminary data showed that purified HTPLO also displayed a similar stimulatory response to benzidine oxidation in the presence of chlorpromazine. CONCLUSION: Both soybean lipoxygenase and purified human term placental lipoxygenase can mediate stimulatory response to the oxidation of benzidine and other xenobiotics in the presence of phenothiazines.
    [Abstract] [Full Text] [Related] [New Search]