title: Consequences of metal exposure on retinoid metabolism in vertebrates: a review.
abstract: What we generally refer to as 'vitamin A' is a group of naturally-occurring molecules structurally similar to retinol that are capable of exerting biological activity. These retinoids are essential to diverse physiological functions including vision, immune response, bone mineralization, reproduction, cell differentiation, and growth. As well, some retinoids have antioxidant properties. Independent studies published over the last few decades have revealed that many fish and wildlife populations living in highly polluted environments have altered retinoid status possibly associated with retinoid metabolic or homeostatic mechanisms. Substantial evidence links organic contaminant exposure with changes in retinoid status in animal populations, but only a few detailed studies have been published implicating inorganic contaminants such as metals. This mini-review selectively deals with field and laboratory studies reporting associations between environmental contaminants, especially trace metals, and alterations in retinoid status. Both essential and non-essential trace metals have been reported to affect retinoid status. This review focuses on metabolic imbalances of retinoids in relation to metal contamination and illustrates possible modes of action. The role of retinoids as antioxidants and their potential as biomarkers of metal contamination are discussed.
authors.affiliation: Institut national de la recherche scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC, Canada G1K 9A9.
authors.forename: M A
authors.initials: MA
authors.lastname: Defo
authors.affiliation: Centre de Recherche TOXEN and Département des Sciences biologiques, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montréal, QC, Canada H3C 3P8.
authors.forename: P A
authors.initials: PA
authors.lastname: Spear
authors.affiliation: Institut national de la recherche scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC, Canada G1K 9A9. Electronic address: patrice.couture@ete.inrs.ca.
authors.forename: P
authors.initials: P
authors.lastname: Couture
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000009:adverse effects / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D001717:Birds; D017753:Ecosystem; D004781:Environmental Exposure / Q000009:adverse effects; D004784:Environmental Monitoring / Q000379:methods; D004785:Environmental Pollutants / Q000009:adverse effects*; D005399:Fishes; D006986:Hypervitaminosis A / Q000378:metabolism; D008322:Mammals; D008670:Metals / Q000009:adverse effects*; D012176:Retinoids / Q000009:adverse effects / Q000378:metabolism*; D018570:Risk Assessment
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D004785:Environmental Pollutants; D008670:Metals; D012176:Retinoids
keywords: Antioxidants; Chronic metal exposure; Retinoid metabolism; Vertebrates