{"title":"Overview: Impact of MRP2 on Toxicology","authors":"M. Vore","doi":"10.1080/08865140390427418","DOIUrl":"https://doi.org/10.1080/08865140390427418","url":null,"abstract":"The identification of the family of multidrug-resistance-associated proteins (MRPs) has provided new understanding regarding mechanisms of absorption, distribution, elimination, and toxicity of both endoand xenobiotics. Just over 10 years ago, Cole et al. (1) identified MRP1, the founding member of this family, in a multidrug-resistant human lung cancer cell line that did not express MDR1 P-glycoprotein. This issue of Comments on Toxicology is devoted to three topics related to MRP2, the second member of this family to be identified, and the role it plays in both mediating and protecting against toxicity. MRP2 (ABCC2) is the transporter that mediates the biliary excretion of numerous drugs and their metabolites. The first article by Christoph Dietrich and colleagues, details several examples in which MRP2 protects the organism from toxicity by preventing the absorption of dietary carcinogens and, conversely, promotes toxicity of chemicals, such as a-naphthylisothiocyanate, by eliminating them from the hepatocyte but concentrating them in bile, where they then induce local damage to cholangiocytes, the cells lining the biliary tree. The article by Ned Ballatori and colleagues summarizes the evidence demonstrating that MRP2 mediates the secretion of glutathione (GSH) into bile, which contributes significantly to the generation of bile flow. MRP2-mediated transport of GSH, either alone or as a part of a complex, is a two-edged sword, resulting in protection of cholangiocytes and enterocytes downstream from the hepatocyte, but also in depletion of the hepatocyte of GSH under certain conditions, such as in the presence of arsenite. MRP2-mediated efflux of GSH","PeriodicalId":402874,"journal":{"name":"Comments on Toxicology","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114825774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Toxicological Effects of Hepatotoxins (Microcystins) on Aquatic Organisms","authors":"José María Monserrat, G. Pinho, J. Yunes","doi":"10.1080/08865140302427","DOIUrl":"https://doi.org/10.1080/08865140302427","url":null,"abstract":"Some cyanobacteria produce microcystins, hepatotoxins with strong cytotoxicity mediated by inhibition of protein phosphatases. New evidence, however, suggests other toxic mechanisms, including oxidative damage and disruption of osmoregulation. Augmented levels of reactive oxygen species, lipid peroxides, and DNA damage were reported after microcystin exposure. The tripeptide glutathione (GSH) is one of the most important antioxidants, and it was reported that microcystin is conjugated with GSH. Microcystin conjugation could deplete the intracellular stores of GSH, leaving the cell more susceptible to oxidative stress. Inhibition of Na + , K + -ATPase by microcystin may be responsible for osmoregulation failure in freshwater fishes.","PeriodicalId":402874,"journal":{"name":"Comments on Toxicology","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126749398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Guest Editor","authors":"Hanan Charaf","doi":"10.1080/08865140302424","DOIUrl":"https://doi.org/10.1080/08865140302424","url":null,"abstract":"The Guest Editor for this issue of Comments on Toxicology is Dr. José M. Monserrat, Professor of Biochemistry in the Department of Physiological Sciences at the Federal University of Rio Grande, Rio Grande, Brazil. Dr. Monserrat is a marine biologist with interest in toxins, especially saltwater phycotoxins. He has a particular interest in the cyanobacteria and the various toxins produced by this organism. Dr. Monserrat has been an active researcher in this field for a number of years and has carried out numerous monitoring programs in Brazil. The following overview of this issue was prepared by Dr. Monserrat.","PeriodicalId":402874,"journal":{"name":"Comments on Toxicology","volume":"311 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121897792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Alvarez, M. Tejuca, I. Pazos, M. E. Lanio, A. Garateix, A. Aneiros
{"title":"Overview of Marine Toxin Research in Cuba","authors":"C. Alvarez, M. Tejuca, I. Pazos, M. E. Lanio, A. Garateix, A. Aneiros","doi":"10.1080/08865140302430","DOIUrl":"https://doi.org/10.1080/08865140302430","url":null,"abstract":"Toxin research in Cuba has made some important contributions to the field in recent decades. Most of the work carried out on marine toxins has been devoted to the isolation, purification, and characterization of polypeptide substances. The purification, molecular, and functional characterization as well as the pharmacological properties of these toxins are revised. The toxin battery described includes new biomolecules: sticholysins I and II, cytolysins from Stichodactyla helianthus; BgK and ShK, two K + channel blockers purified from Bunodosoma granulifera and S. helianthus, respectively; and BgII and III, two Na + channeltoxinsfrom B. granulifera.","PeriodicalId":402874,"journal":{"name":"Comments on Toxicology","volume":"3 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113961975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Yunes, N. T. Cunha, L. P. Barros, L. Proença, José María Monserrat
{"title":"Cyanobacterial Neurotoxins from Southern Brazilian Freshwaters","authors":"J. Yunes, N. T. Cunha, L. P. Barros, L. Proença, José María Monserrat","doi":"10.1080/08865140302426","DOIUrl":"https://doi.org/10.1080/08865140302426","url":null,"abstract":"Blooms of Cylindrospermopsis raciborskii and Anabaena spiroides were studied in relation to their toxins composition, geographical locations, and other characteristics of the waters in the southern region of Brazil. All forms of Cylindrospermopsis were paralytic shellfish toxin producers, with a similar profile of the toxins. Anabaena blooms were studied in relation to the production of anatoxin-a(S). In all samples containing Anabaena spiroides, a positive result was found when the AChE inhibition technique was used. Methods applied for both studies are very convenient for monitoring this large region and give a reasonable view of the present situation of water reservoirs in southern Brazil.","PeriodicalId":402874,"journal":{"name":"Comments on Toxicology","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114555242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Paralytic shellfish poisoning phycotoxins: Occurrence in South America","authors":"N. Lagos","doi":"10.1080/08865140302429","DOIUrl":"https://doi.org/10.1080/08865140302429","url":null,"abstract":"This is a review of the regional (South America) harmful algae blooms associated with paralytic shellfish poisoning (PSP) phycotoxin producers. This review provides a survey of the most relevant recorded events known to have been caused by microalgae that are PSP producers in this region. The geographical distribution of harmful species of PSP phycotoxins producers in sea and inland fresh water are shown. The variation of molluscs toxicity measured by the mouse bioassay, high performance liquid chromatography with fluorescence detection, and analysis by liquid chromatography and mass spectroscopy of these PSP phycotoxins in Argentina, Brazil, Chile, Uruguay, and Venezuela is summarized. I hope this review provides reference material suitable for researchers, students, managers, health professionals, and political authorities. Another goal is to stimulate research in this area to answer critical questions to improve our understanding of PSP-producing harmful algal bloom species and the significant effects that they have upon aquatic systems and our lives in this part of the world.","PeriodicalId":402874,"journal":{"name":"Comments on Toxicology","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122225000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Biological Effects of Toxins","authors":"José María Monserrat","doi":"10.1080/08865140302431","DOIUrl":"https://doi.org/10.1080/08865140302431","url":null,"abstract":"This special issue is devoted to the analysis of the effects of toxins produced by different kinds of organisms. Toxinology is the science that studies the chemical properties and biological effects of toxic substances produced or accumulated in living organisms. Probably, if one term were used to define toxinology, the word would be ‘‘diversity’’ Diversity of organisms that produce tremendously diverse chemical compounds that in turn possess diverse biological targets, such as ion channels or enzymes (acetylcholinesterase or phosphatases). An important point of this issue is that all the contributors are researchers born in Latin American countries. This fact reflects the importance and efforts that are devoted to this topic in this region. As one of the contributors stated, the extended coastal regions and coral reefs of Latin American countries are rich with biological diversity of toxin-producing organisms, like Cnidarians for example. As a consequence of the chemical diversity, the approaches that the different authors employed in their reviews are diverse. Some articles are of a biochemical and pharmacological nature, others focus on the detection and quantification of toxins in aquatic environments from a more ecotoxicological point of view. Finally, toxinology as a science opens the door for the potential therapeutics use of natural compounds, a fact well stated in several of the reviews in this issue. In the last several years, the study of marine-natural products has gained attention through improved biological screening methods (1). In several Latin American countries, zootherapy and phytotherapy, using chemicals derived directly or indirectly from animals and vegetable sources has become common practice (2). We expect in the near future that a convergence of ideas from toxinology and ethnopharmacology will develop. This last point also stresses that the discovery of molecules beneficial for human health is closely related to the preservation of the natural","PeriodicalId":402874,"journal":{"name":"Comments on Toxicology","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134379488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Recent Advances in Cnidarian Neurotoxin Research","authors":"M. Torres-Ramos, M. Aguilar","doi":"10.1080/08865140302428","DOIUrl":"https://doi.org/10.1080/08865140302428","url":null,"abstract":"Marine organisms have provided an interesting array of biologically active peptides and proteins. Many of these compounds have proven to be excellent tools for probing biological functions as they are highly site-specific in their actions. In this review, we have highlighted recent work regarding Cnidarian toxins from hydrozoans, scyphozoans, cubozoans, and anthozoans. Structure-activity studies of anthozoan toxins indicate potential therapeutical applications.","PeriodicalId":402874,"journal":{"name":"Comments on Toxicology","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131769559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
José Carlos de Freitas, Marisa Rangel, Joacir Stolarz Oliveira, A. J. Zaharenko, E. Rozas
{"title":"An Outline of Marine Toxinology Studies in the Brazilian coast","authors":"José Carlos de Freitas, Marisa Rangel, Joacir Stolarz Oliveira, A. J. Zaharenko, E. Rozas","doi":"10.1080/08865140302425","DOIUrl":"https://doi.org/10.1080/08865140302425","url":null,"abstract":"Over the last 20 years, our group has collected different species of marine organisms occurring in the Brazilian coastline. The pharmacological approach is the evaluation of effects of organic extracts, or purified and isolated compounds in laboratory animals, organs, tissues, and cells to define the profile of biological activity and the mechanisms of action. Different bioassays are currently used including hemolytic cytotoxicity, neurotoxicity, and neuromuscular junction preparations. Furthermore, biologically active substances are being isolated from dinoflagellates, sponges, sea anemones, and puffer fish collected in the Sa ¨ o Sebastia ¨ o Channel (Sa ¨ o Paulo State, Brazil) and from the mollusk Conus regius collected in the Fernando de Noronha Archipelago, Pernambuco State, Brazil. These results suggest it may be very worthwhile to extend our studies for new bioactive compounds along the Brazilian coastline.","PeriodicalId":402874,"journal":{"name":"Comments on Toxicology","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128236540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Metal-Induced Modulation of Redox Cell-Signaling in the Immune System","authors":"W. Lutz, W. Wąsowicz","doi":"10.1080/08865140302422","DOIUrl":"https://doi.org/10.1080/08865140302422","url":null,"abstract":"A large number of metals in the environment enter the human body and exert diverse toxic effects on the immune system-forming cells. These effects may lead to the death of the cells through the mechanism responsible for apoptosis or necrosis, as well as for activation or suppression of immune functions. Activation or suppression of lymphocytes and antigen-presenting cells depends on the kind and concentration of metals in target cells. The metal-generated changes in protein activity, which induce signaling pathways, as well as changes in expression of genes able to regulate the production of such protein molecules as cytokines and their receptors and surface adhesion molecules, predominate in the immunotoxic effects. Insufficient activation or inhibited production of these proteins is manifested by a decreased immunity of the organism (immuno-suppression), whereas their overactivation induces hypersensitivity (allergy, autoimmunization). A growing amount of data confirm that the activation of proteins involved in cellular signaling and the activation of expression of genes regulating the synthesis of proteins participating in the immune response are associated with oxidative metabolism of immune cells. These data also provide evidence that the modulation effect of metals on the immune response proceeds through influencing the mechanisms that control the production of reactive oxygen species.","PeriodicalId":402874,"journal":{"name":"Comments on Toxicology","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122848151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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