AhR-zprostředkovaná aktivita huminových látek a jejich fotodegradačních produktů
| Title in English | AhR-mediated activity of humic substances and their photo-degradation products |
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| Authors | |
| Year of publication | 2007 |
| Type | Article in Proceedings |
| Conference | Toxicita a biodegradabilita odpadů a látek významných ve vodním prostředí - XIII. Toxikologická konference |
| MU Faculty or unit | |
| Citation | |
| Field | Water pollution and control |
| Description | Humic substances (HS) are ubiquitous in the environment - they constitute the major components of dissolved organic matter in waters and the major part of materials that comprise soil organic matter. However, some studies indicate that HS can induce a direct adverse effect on human health and hormone-like effects on fish, amphibians and invertebrates. HS molecules contain number of aromatic rings and conjugated double bonds - the so called chromophores. That implies irradiation of dissolved HS can lead to a series of photochemical reactions which can act on the HS itself, or on other substances present in aquatic environment along with HS such as e.g. xenobiotics. In our previous study, we have found significant interactions of pure humic acids (HA) with cytosolic aryl hydrocarbon receptor (AhR). The reporter gene in vitro bioassay with H4IIE-luc cells was used for determination of AhR-mediated activity of HA. H4IIE-luc are stably transfected hepatoma cells with a luciferase reporter gene that is activated via AhR. Irradiation of five different aqueous HA samples were carried out in pyrex tubes using low-pressure mercury lamp. Concentrations of irradiated HA samples were 50 mg/L, and irradiation times were from 0 to 52 hours. In this contribution, we summarize our new findings on alteration of AhR-mediated activity of irradiated HS under the lab conditions. Additionally, supposed mechanisms of observed irradiation-induced decrease in AhR-mediated activity of dissolved HS are discussed. |
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