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

Search MEDLINE/PubMed


  • Title: Effects of peroxisome proliferators on glutathione and glutathione-related enzymes in rats and hamsters.
    Author: O'Brien ML, Cunningham ML, Spear BT, Glauert HP.
    Journal: Toxicol Appl Pharmacol; 2001 Feb 15; 171(1):27-37. PubMed ID: 11181109.
    Abstract:
    Peroxisomeproliferators (PPs) cause hepatomegaly, peroxisome proliferation, and hepatocarcinogenesis in rats and mice. Conversely, hamsters are less responsive to these compounds. PPs increase peroxisomal beta-oxidation and P4504A subfamily activity, which has been hypothesized to result in oxidative stress. We hypothesized that differential modulation of glutathione-related defenses could account for the resulting difference in species susceptibility following PP administration. Accordingly, we measured glutathione S-transferase (GST), glutathione peroxidase (GPx), and glutathione reductase (GR) activities, and total glutathione (GSH) in male Sprague-Dawley rats and Syrian hamsters fed two doses of three known peroxisome proliferators [dibutylphthalate (DBP), gemfibrozil, and Wy-14,643] for 6, 34, or 90 days. In rats, decreases in GR, GST, and selenium-dependent GPx were observed following PP treatment at various time points. In hamsters, we observed higher basal levels of activities for GR, GST, and selenium-dependent GPx compared to rats. In addition, hamsters showed decreases in GR and GST activities following PP treatment. Interestingly, selenium-dependent GPx activity was increased in hamsters following treatment with Wy-14,643 and DBP. Treatment for 90 days with Wy-14,643 resulted in no change in GPx1 mRNA in rats and increased GPx1 mRNA in hamsters. Sporadic changes in total GSH and selenium-independent GPx were observed in both species. This divergence in the hydrogen peroxide detoxification ability between rats and hamsters could be a contributing factor in the proposed oxidative stress mechanism of PPs observed in responsive and nonresponsive species.
    [Abstract] [Full Text] [Related] [New Search]