Oxidative Stress and Antioxidant Defenses in Antarctic Marine Organisms

Federal Geographic Data Committee (FGDC) Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: ANSALDO, Martin
Publication_Date: Unknown
Title: Oxidative Stress and Antioxidant Defenses in Antarctic Marine Organisms
Edition:
Geospatial_Data_Presentation_Form:
Series_Information:
Series_Name:
Issue_Identification:
Publication_Information:
Publication_Place:
Publisher:
Other_Citation_Details:
Online_Linkage:
Description:
Abstract:
Principal Objectives -Determination of the oxidative stress levels in marine Antarctic organisms (vertebrates and invertebrates), by physiological, biochemical and histochemical techniques: -Comparative study of antioxidant defences. Hypotheses: - The marine Antarctic medium presents extreme environmental conditions which induce oxidative stress. - The adaptation to cold environments implies changes in the lipid composition towards a higher proportion of polyunsaturated fatty acids, which are more susceptible to peroxidation. - Antarctic marine organisms possess particular adaptations in their antioxidant defences for maintaining the stability of cellular components. - Pollution caused by human activity augments the presence of prooxidant compounds in the marine environment. Project The normal use of oxygen by aerobic organisms produces several active species of oxygen. The first derivative that forms is the anion superoxide (O2-) that is a species with a negative charge, slightly diffusible and relatively stable, with characteristics of free radical (elements with a free electron). The second product of reduction is hydrogen peroxide (H2O2), a highly diffusible, stable molecule. The union of these two species, in the presence of hemoproteins (for example: hemoglobin, hemocyanin, etc.) containing prosthetic group transition metals, generates a new, extremely reactive species, the radical hydroxyl (OH-). This radical has a very short half life and, therefore, interacts with compounds in its en be they proteins, lipids or acids, producing reversible or irreversible damage depending on its concentration. Aerobic animals and vegetables have within their cells enzymatic and nonenzymatic antioxidant defenses. Within the enzymatic defenses we found: a) superoxide dismutase (SOD), b) catalase (CAT) and c) glutathione peroxidase (GPx): a) Superoxide dismutase (SOD) with superoxide (O2-) anion produces hydrogen peroxide (equation 1): O2- + 2 H+ ---> H2O2 (1) This enzyme contains prosthetic group transition metals for oxidation - reduction necessary for the dismutation of this species. b) Metabolized CAT to hydrogen peroxide turning it to water (equation 2): 2H2O2 ---> 2H2O + O2 (2) This enzyme is peroxisomal in behavior, and, in addition to its catalytic function, it can conduct a peroxidative battle with much lesser efficiency. c) GPx can also transform hydrogen peroxide into water and additionally metabolizes organic peroxides such as lipoperoxides (equation 3): 2 GSH + ROOH ---> GSSG + ROH + H2O (3) This enzyme uses as substrate a non-enzymatic antioxidant, - reduced glutathione (GSH). This antioxidant is distributed widely in different organs. Its function is fundamental to maintaining oxidation balance. Another important non-enzymatic antioxidant is ascorbic acid (vitamin C). Ascorbic acid is crucial in the replacement of the antioxidant activity of vitamin E. Also, vitamin E, like vitamin A, is a liposoluble that is found in cell membranes, catching or extinguishing excited species that are generated in the reduction of oxygen. Potentially, oxidative stress is experienced by aerobic organisms when antioxidant defenses are surpassed by pro-oxidating forces. This mechanism has been implied in carcinogenesis, ischemia and reperfusion damage, inflammation and aging. Evidence suggests that the health of aquatic organisms is linked to the level of oxidative stress to which they may have been exposed (Di Giulio et al., 1989). In particular, regarding processes by which natural atmospheric conditions or the presence of pollutants have increased the level of pro-oxidating substances. The extreme physical characteristics of the Antarctic marine environment provide a challenge in confronting the oxidative metabolism of the organisms that inhabit it, since natural situations like, for example, the high oxygen content in the cold waters or greater exposure to UV radiation (due to the hole in the ozone layer), would have to lead to an adaptation in the activity of metabolizing enzymes of the reduced oxygen species, and non-enzymatic antioxidants. Similarly, the presence of transition metals and/or xenobiotic substances in the water produce oxidative stress in the organisms exposed to these substances (Winston, 1991). Project duration: 2002-2004 Espanol: Como consecuencia de la utilizacion normal del oxigeno por los organismos aerobicos, se producen varias especies activas del oxigeno. El primer derivado que se forma es el anion superoxido (O2-) que es una especie con carga, poco difusible y relativamente estable, con caracteristicas de radical libre (elementos con un electron desapareado). El segundo producto de la reduccion es el peroxido de hidrogeno (H2O2), molecula estable altamente difusible. La union de estas dos especies, en presencia de hemoproteinas (por ejemplo: hemoglobina, hemocianina, etc.) que contengan metales de transicion en su grupo prostetico, genera una nueva especie extremadamente reactiva que es el radical hidroxilo (OH-). Este radical tiene una vida media muy corta por lo que interactua con los compuestos de sus alrededores ya sean proteinas, lipidos o acidos nucleicos, produciendo danos de caracter reversible o irreversible dependiendo de su concentracion. Los animales y vegetales aerobios tienen dentro de sus celulas defensas antioxidantes enzimaticas y no enzimaticas radical hidroxilo (OH). Este radical tiene una vida media muy corta por lo que interactua con los compuestos de sus alrededores ya sean proteinas, lipidos o acidos nucleicos, produciendo danos de caracter reversible o irreversible dependiendo de su concentracion. Los animales y vegetales aerobios tienen dentro de sus celulas defensas antioxidantes enzimaticas y no enzimaticas. Dentro de las defensas enzimaticas encontramos: a) superoxido dismutasa (SOD), b) catalasa (CAT) y c) glutation peroxidasa (GPx). a) La SOD dismuta el anion superoxido a peroxido de hidrogeno (ecuacion 1). O2- + 2 H+ ---> H2 O2 (1) Esta enzima contiene metales de transicion en su grupo prostetico con los que realiza las oxido - reducciones necesarias para la dismutacion de esta especie. b) La CAT metaboliza al peroxido de hidrogeno convirtiendolo en agua (ecuacion 2). 2 H2O2 ---> 2 H2O + O2 (2) Esta enzima es de ubicacion peroxisomal y ademas de su funcion catalitica puede realizar una accion peroxidativa con mucha menor eficiencia. c) La GPx tambien puede transformar el peroxido de hidrogeno en agua y ademas metaboliza peroxidos de tipo organicos tales como los lipoperoxidos (ecuacion 3) 2 GSH + ROOH ---> GSSG + ROH + H2O (3) Esta enzima utiliza como sustrato a un antioxidante no enzimatico, que es el glutation reducido (GSH). Este antioxidante se encuentra ampliamente distribuido en los distintos organos. Su funcion es fundamental para mantener el equilibrio oxidativo. Otro de los antioxidantes no enzimaticos importantes es el acido ascorbico (vitamina C). Este compuesto es fundamental en la reposicion de la actividad antioxidante de la vitamina E. Tanto la vitamina E como la A son compuestos de caracteristicas liposolubles que se encuentran en la membrana de las celulas atrapando o apagando las especies excitadas que se generan en la reduccion del oxigeno. El estres oxidativo, potencialmente, es experimentado por todos los organismos aerobicos cuando las defensas antioxidantes son superadas por las fuerzas prooxidantes. Este mecanismo se ha visto implicado en carcinogenesis, dano de isquemia y reperfusion, inflamacion y envejecimiento. Existe evidencia que indica que la salud de los organismos acuaticos puede estar ligada al nivel de estres oxidativo al que se encuentran expuestos (Di Giulio et al., 1989). En particular sobre aquellos procesos por los cuales las condiciones naturales del ambiente o la presencia de sustancias contaminantes hubiesen incrementado el nivel de prooxidantes presentes. Las caracteristicas fisicas extremas del medio ambiente marino antartico, plantean un desafio a confrontar sobre el metabolismo oxidativo de los organismos que lo habitan, ya que situaciones naturales como, por ejemplo, el alto contenido de oxigeno de sus frias aguas o la mayor exposicion a la radiacion UV (debido a la presencia del agujero en la capa de ozono), deberian conducir a una adaptacion en la actividad de las enzimas metabolizadoras de las especies reducidas del oxigeno y en los niveles de los antioxidantes no enzimaticos. Del mismo modo la presencia de metales de transicion y/o de sustancias xenobioticas organicas en el agua se sabe que producen estres oxidativo en los organismos expuestos a dichas sustancias (Winston, 1991). e-mail: tincho@bg.fcen.uba.ar Nombre del Proyecto: Estres oxidativo y defensas antioxidantes en organismos marinos antarticos. (Proyecto en cooperacion con la Universidad de Buenos Aires) Director: Lic. Martin Ansaldo Co-Director: Dr. Carlos Marcelo Luquet
Purpose:
Not Available
Supplemental_Information:
Not Available
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20020101
Ending_Date: 20041231
Currentness_Reference:Unknown
Status:
Progress: In Work
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Description_of_Geographic_Extent:
Bounding_Coordinates:
West_Bounding_Coordinate: -180.0
East_Bounding_Coordinate: 180.0
North_Bounding_Coordinate: -62.83
South_Bounding_Coordinate: -90.0
Keywords:
Theme:
Theme_Keyword_Thesaurus: GCMD SCIENCE PARAMETERS
Theme_Keyword_Thesaurus: GCMD PLATFORM
Theme_Keyword_Thesaurus: PROJECT
Theme_Keyword_Thesaurus: ANCILLARY KEYWORDS
Theme_Keyword_Thesaurus: ISO TOPIC CATEGORY
Theme_Keyword: EARTH SCIENCE > BIOSPHERE > TERRESTRIAL ECOSYSTEMS
Theme_Keyword: EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > WATER QUALITY/WATER CHEMISTRY > ACID DEPOSITION
Theme_Keyword: EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > WATER QUALITY/WATER CHEMISTRY > CARCINOGENS
Theme_Keyword: EARTH SCIENCE > BIOSPHERE > AQUATIC ECOSYSTEMS
Theme_Keyword: EARTH SCIENCE > BIOSPHERE > ECOLOGICAL DYNAMICS > SPECIES/POPULATION INTERACTIONS > EVOLUTIONARY ADAPTATION
Theme_Keyword: EARTH SCIENCE > BIOSPHERE > ECOLOGICAL DYNAMICS > SPECIES/POPULATION INTERACTIONS > POPULATION DYNAMICS
Theme_Keyword: EARTH SCIENCE > BIOSPHERE > ECOLOGICAL DYNAMICS > ECOTOXICOLOGY > TOXICITY LEVELS
Theme_Keyword: GROUND STATIONS
Theme_Keyword: OSADAMO > OXIDATIVE STRESS AND ANTIOXIDANT DEFENSES IN ANTARCTIC MARINE ORGANISMS
Theme_Keyword: Environmental Conditions
Theme_Keyword: Oxidative Stress
Theme_Keyword: Polyunsaturated Fatty Acids
Theme_Keyword: Peroxidation
Theme_Keyword: Cellular Components
Theme_Keyword: Anion Superoxido (o2-)
Theme_Keyword: Peroxido De Hidrogeno (h2o2)
Theme_Keyword: Hemoglobina
Theme_Keyword: Hemocianina
Theme_Keyword: Superoxido Dismutasa (sod)
Theme_Keyword: Catalasa (cat)
Theme_Keyword: Glutation Peroxidasa (gpx)
Theme_Keyword: BIOTA
Theme_Keyword: ENVIRONMENT
Theme_Keyword: GEOSCIENTIFIC INFORMATION
Theme_Keyword: INLAND WATERS
Place:
Place_Keyword_Thesaurus: GCMD
Place_Keyword: OCEAN > SOUTHERN OCEAN
Place_Keyword: GEOGRAPHIC REGION > POLAR
Access_Constraints: Not Available
Use_Constraints:
Not Available
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: MARTIN ANSALDO
Contact_Position: TECHNICAL CONTACT
Contact_Position: INVESTIGATOR
Contact_Address:
Address_Type: Mailing and Physical Address
Address: Departamento Ciencias Biologicas
Address: Cerrito 1248 C1010AAZ
City: Buenos Aires
Country: Argentina
Contact_Voice_Telephone: 54 11 4812 0071-72 (EXT. 117)
Contact_Facsimile_Telephone: 54 11 4812 1689
Contact_Electronic_Mail_Address: tincho@bg.fcen.uba.ar
Back to Top
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
Not Available
Logical_Consistency_Report:
Not Available
Completeness_Report:
Not Available
Lineage:
Process_Step:
Process_Description:
Not Available
Process_Date: Unknown
Back to Top
Spatial_Reference_Information:
Back to Top
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: AR/CDA > Centro de Datos Antarticos, Argentina
Contact_Person: CELIA ELBA IZQUIERDO
Contact_Position: DATA CENTER CONTACT
Contact_Address:
Address_Type: Mailing and Physical Address
Address: Centro de Datos Antarticos
Address: Direccion Nacional del Antartico
Address: Instituto Antartico Argentino
Address: Cerrito 1248
City: Capital Federal
Postal_Code: C1010AAZ
Country: ARGENTINA
Contact_Voice_Telephone: 54-11-4812-2086
Contact_Facsimile_Telephone: 54-11-4812-2086
Contact_Electronic_Mail_Address: celeiz_antar@hotmail.com
Contact_Electronic_Mail_Address: celeiz@dna.gov.ar
Contact_Electronic_Mail_Address: cda@dna.gov.ar
Resource_Description: CDA_AR_BIO_OXIDATIVE_STRESS
Distribution_Liability:
Not Available
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: Not Available
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
http://www.dna.gov.ar/
Access_Instructions:
DATA CENTER URL
Digital_Transfer_Option:
Fees: Not Available
Back to Top
Metadata_Reference_Information:
Metadata_Date: 20030521
Metadata_Review_Date: 20051103
Metadata_Future_Review_Date: 20040523
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: CELIA ELBA IZQUIERDO
Contact_Position: DIF AUTHOR
Contact_Address:
Address_Type: Mailing and Physical Address
Address: Centro de Datos Antarticos
Address: Direccion Nacional del Antartico
Address: Instituto Antartico Argentino
Address: Cerrito 1248
City: Capital Federal
Postal_Code: C1010AAZ
Country: ARGENTINA
Contact_Voice_Telephone: 54-11-4812-2086
Contact_Facsimile_Telephone: 54-11-4812-2086
Contact_Electronic_Mail_Address: celeiz_antar@hotmail.com
Contact_Electronic_Mail_Address: celeiz@dna.gov.ar
Contact_Electronic_Mail_Address: cda@dna.gov.ar
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Back to Top
[ Update this Record ]


Link to Web Site