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: Induction of cytokine gene expression in mice after repeated and subchronic oral exposure to vomitoxin (Deoxynivalenol): differential toxin-induced hyporesponsiveness and recovery.
    Author: Zhou HR, Yan D, Pestka JJ.
    Journal: Toxicol Appl Pharmacol; 1998 Aug; 151(2):347-58. PubMed ID: 9707511.
    Abstract:
    A single oral exposure to vomitoxin (VT) in mice has been previously shown to induce in lymphoid tissues the rapid expression of cytokine mRNAs that are produced by both macrophages and T cells. To determine whether prior VT exposures positively or negatively modulate the cytokine response to the toxin in this model, we evaluated the effects of short-term oral (two to seven consecutive daily doses) and subchronic dietary (4 weeks) exposure to VT on expression of a panel of cytokine mRNAs. Effects of a single oral exposure to 0, 5, and 25 mg/kg body wt of VT or of two such daily consecutive doses on splenic cytokine mRNA abundance were compared 2 h after the last toxin administration using RT-PCR in combination with hybridization analysis. While robust cytokine mRNA responses occurred after a single VT exposure, attenuated but significant induction of interleukin (IL)-6, tumor necrosis factor (TNF)-alpha, IL-1beta, and IL-12p40 mRNA was observed after a second VT dose. Similar but insignificant trends occurred with interferon (IFN)-gamma, IL-2, IL-4, and IL-10 mRNAs. Serum TNF-alpha and IL-6 proteins mimicked cytokine mRNA responses although attenuation responses were less marked. Mice were also dosed with VT at 0, 0.5, 2, or 5 mg/kg body wt consecutively for 2, 4, or 7 days and cytokine mRNAs were assessed 2 h after the last treatment in spleen and Peyer's patches. Upon exposure to 2 and 5 mg/kg body wt VT, the relative abundance of IL-1beta, IL-6, TNF-alpha, IL-12 p35, IL-12p40, IL-2, and IL-10 mRNAs increased with dose frequency whereas IFN-gamma and IL-4 mRNAs were unaffected. When mice were fed 0, 10, and 25 ppm VT for 4 weeks, increased expression of mRNAs for TNF-alpha, IL-2, IFN-gamma, and IL-10 was most prominent. However, when VT-fed mice were also challenged with an oral dose of VT equivalent to daily intake at 2 h prior to RNA isolation, vigorous mRNA responses were observed for IL-1beta, IL-6, TNF-alpha, IL-12p40, IL-12p35, IL-2, IFN-gamma, IL-4, and IL-10. In general, spleens were more responsive to the above effects than Peyer's patches. The results indicate that, following a single prior VT exposure, a significant but attenuated cytokine mRNA response occurred upon a second VT treatment. This hyporesponsiveness was overcome upon repeated exposures to the toxin. These data further support the contention that elevated cytokine expression may play a contributory role in the pathophysiologic and immunologic effects of VT and other trichothecene mycotoxins.
    [Abstract] [Full Text] [Related] [New Search]