Pacific Ocean–Wide Profile of CYP1A1 Expression, Stable Carbon and Nitrogen Isotope Ratios, and Organic Contaminant Burden in Sperm Whale Skin Biopsies
| Autor: | Letizia Marsili, Silvia Maltese, Stephen B. Cox, Nadia Rubio-Cisneros, Céline A.J. Godard-Codding, Roger Payne, Kim Pinkerton, Maria Cristina Fossi, John C. Cannon, Victoria J. Rowntree, Ildiko Polyak, Luciano O. Valenzuela, Adam G. West, John J. Stegeman, Iain Kerr, Sarah L. Mesnick, Rebecca M. Clark |
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| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
0106 biological sciences
Male Health Toxicology and Mutagenesis Science Selections Biopsy biomarkers CYP1A1 cytochrome P450 marine ecosystem marine mammal PAH PCB PHAH sperm whale stable isotope 010501 environmental sciences 01 natural sciences chemistry.chemical_compound Food chain Blubber Hexachlorobenzene Water Pollution Chemical Water pollution Trophic level media_common Skin Carbon Isotopes biology Ecology Stable isotope ratio Marine reserve Polychlorinated Biphenyls Oceanography Adipose Tissue Body Burden Female Environmental Monitoring Pollution media_common.quotation_subject education Cetacea News DDT Marine mammal biology.animal Sperm whale Cytochrome P-450 CYP1A1 Animals Marine ecosystem Ecosystem 14. Life underwater 0105 earth and related environmental sciences Pollutant Pacific Ocean Nitrogen Isotopes Whale 010604 marine biology & hydrobiology Research Public Health Environmental and Occupational Health 15. Life on land biology.organism_classification Hydrocarbons chemistry 13. Climate action Water Pollutants Chemical |
| Zdroj: | Environmental Health Perspectives |
| ISSN: | 1552-9924 0091-6765 |
| Popis: | Expression of the enzyme CYP1A1 in the skin of marine mammals has been shown by multiple studies to indicate exposure to organic pollutants in a dose-dependent manner. A new large-scale monitoring study investigated whether analysis of dermal CYP1A1 expression and organic pollutants in sperm whales (Physeter macrocephalus) could reveal oceanwide geographical trends in chemical exposure [EHP 119(3):337–343; Godard-Codding et al]. This is the first known study to assess broad geographic trends in CYP1A1 expression, stable carbon and nitrogen isotopes, and organic pollutant burdens in a threatened whale species. The authors used immunochemistry to analyze CYP1A1 expression in skin and blubber samples collected from 234 sperm whales from five Pacific Ocean regions. Variation in the whales’ trophic level (position in the food chain) was examined by using mass spectrometry to measure nitrogen isotopes in skin samples; enrichment of an animal’s tissue nitrogen is known to occur as the animal eats higher on the food chain. The general latitude frequented by the whales—a reflection of where the whales were likely to have been exposed to pollution—was determined by analyzing carbon isotope ratios. The whales exhibited significant regional differences in CYP1A1 expression. Expression was highest among whales from the Galapagos Islands, a United Nations World Heritage marine reserve, and lowest among whales from sites farthest away from continents. Differences in the whales’ age, sex, and diet did not appear to explain regional differences but could not be ruled out unequivocally. This study did not show a significant correlation between CYP1A1 expression in skin cells and actual pollutant burden in blubber, as measured by analyzing eight sex-specific pooled samples for burdens of polycyclic aromatic hydrocarbons, hexachlorobenzene, polychlorinated biphenyls, and the pesticide DDT, then comparing them with CYP1A1 immunohistochemistry scores estimated for the pooled samples. However, the small size of the individual biopsies allowed under standards for humane biopsying of marine mammals prevented detailed chemical analyses and limited the power to detect significant associations. Also, the biopsies were limited to the outer blubber layer, which is less metabolically active than deeper tissue. Studies in bottlenose dolphins have shown that CYP1A1 expression in the skin is more strongly related to pollutants measured in deeper blubber than in blubber closer to the skin surface; whether such stratification happens in other cetaceans requires further study. The study succeeded at identifying regional differences in CYP1A1 expression, providing a baseline for this known biomarker of exposure to organic pollutants. Future studies that profile CYP1A1 expression in cetacean skin biopsies oceanwide are warranted to explore the global distribution of biochemically relevant levels of these chemicals. |
| Databáze: | OpenAIRE |
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