Inhibition of gap junctional intercellular communication (GJIC) is affiliated with tumor promotion process and it has been employed as an in vitro biomarker for evaluation of tumor promoting effects of chemicals. In the present study we investigated combined effects of anthropogenic environmental contaminants 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153) and fluoranthene, cyanotoxins microcystin-LR and cylindrospermopsin, and extracts of laboratory cultures of cyanobacteria Aphanizomenon gracile and Cylindrospermopsis raciborskii, on GJIC in the rat liver epithelial cell line WB-F344. Binary mixtures of PCB 153 with fluoranthene and the mixtures of the two cyanobacterial strains elicited simple additive effects on GJIC after 30 min exposure, whereas microcystin-LR and cylindrospermopsin neither inhibited GJIC nor altered effects of PCB 153 or fluoranthene. However, synergistic effects were observed in the cells exposed to binary mixtures of anthropogenic contaminants (PCB 153 or fluoranthene) and cyanobacterial extracts. The synergistic effects were especially pronounced after prolonged (6-24h) co-exposure to fluoranthene and A. gracile extract, when mixture caused nearly complete GJIC inhibition, while none of the individual components caused any downregulation of GJIC at the same concentration and exposure time. The effects of cyanobacterial extracts were independent of microcystin-LR or cylindrospermopsin, which were not detected in cyanobacterial biomass. It provides further evidence on the presence of unknown tumor promoting metabolites in cyanobacteria. Clear potentiation of the GJIC inhibition observed in the mixtures of two anthropogenic contaminants and cyanobacteria highlight the importance of combined toxic effects of chemicals in complex environmental mixtures.

• MeSH
• alkaloidy MeSH
• Aphanizomenon metabolismus   MeSH
• bakteriální toxiny MeSH
• buněčné extrakty toxicita   MeSH
• buněčné linie MeSH
• Cylindrospermopsis metabolismus   MeSH
• epitelové buňky účinky léků   metabolismus   MeSH
• fluoreny toxicita   MeSH
• karcinogeny toxicita   MeSH
• krysa rodu Rattus MeSH
• látky znečišťující životní prostředí toxicita   MeSH
• mezerový spoj účinky léků   metabolismus   MeSH
• mezibuněčná komunikace účinky léků   fyziologie   MeSH
• mikrocystiny toxicita   MeSH
• mořské toxiny MeSH
• polychlorované bifenyly toxicita   MeSH
• synergismus léků MeSH
• toxiny kmene Cyanobacteria MeSH
• uracil analogy a deriváty   toxicita   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 2,4,5,2',4',5'-hexachlorobiphenyl MeSH Prohlížeč
• alkaloidy MeSH
• bakteriální toxiny MeSH
• buněčné extrakty MeSH
• cyanoginosin LR MeSH Prohlížeč
• cylindrospermopsin MeSH Prohlížeč
• fluoranthene MeSH Prohlížeč
• fluoreny MeSH
• karcinogeny MeSH
• látky znečišťující životní prostředí MeSH
• mikrocystiny MeSH
• mořské toxiny MeSH
• polychlorované bifenyly MeSH
• toxiny kmene Cyanobacteria MeSH
• uracil MeSH

Here is presented some of the first information on interactions of compounds produced by cyanobacteria and green algae with estrogen receptor signaling. Estrogenic potency of aqueous extracts and exudates (culture spent media with extracellular products) of seven species of cyanobacteria (10 different laboratory strains) and two algal species were assessed by use of in vitro trans-activation assays. Compounds produced by cyanobacteria and algae, and in particular those excreted from the cells, were estrogenic. Most exudates were estrogenic with potencies expressed at 50% of the maximum response under control of the estrogen receptor ranging from 0.2 to 7.2 ng 17β-estradiol (E(2)) equivalents (EEQ)/L. The greatest estrogenic potency was observed for exudates of Microcystis aerigunosa, a common species that forms water blooms. Aqueous extracts of both green algae, but only one species of cyanobacteria (Aphanizomenon gracile) elicited significant estrogenicity with EEQ ranging from 15 to 280 ng 17β-estradiol (E(2))/g dry weight. Scenedesmus quadricauda exudates and extracts of Aphanizomenon flos-aquae were antagonistic to the ER when coexposed to E(2). The EEQ potency was not correlated with concentrations of cyanotoxins, such as microcystin and cylindrospermopsin, which suggests that the EEQ was comprised of other compounds. The study demonstrates some differences between the estrogenic potency of aqueous extracts prepared from the same species, but of different origin, while the effects of exudates were comparable within species. The observed estrogenic potencies are important namely in relation to the possible mass expansion of cyanobacteria and release of the active compounds into surrounding water.

• MeSH
• Aphanizomenon metabolismus   MeSH
• biotest MeSH
• chemické látky znečišťující vodu metabolismus   farmakologie   MeSH
• Chlorophyta metabolismus   MeSH
• endokrinní disruptory metabolismus   farmakologie   MeSH
• estradiol metabolismus   farmakologie   MeSH
• estrogeny metabolismus   farmakologie   MeSH
• eutrofizace MeSH
• exsudáty a transsudáty chemie   MeSH
• mezibuněčná komunikace fyziologie   MeSH
• Microcystis účinky léků   MeSH
• receptory pro estrogeny metabolismus   MeSH
• sinice metabolismus   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• endokrinní disruptory MeSH
• estradiol MeSH
• estrogeny MeSH
• receptory pro estrogeny MeSH