pollution by xenobiotics : biomarkers for early detection of pollution effects ibon cancio...
TRANSCRIPT
POLLUTION BY XENOBIOTICS :BIOMARKERS FOR EARLY
DETECTION OF POLLUTION EFFECTS
Ibon Cancio
EUSKAL HERRIKO UNIBERTSITATEA
UNIVERSITY OF THE BASQUE COUNTRYeman ta zabal zazu
DEPARTMENT OF ZOOLOGY AND ANIMAL CELL DYNAMICS
POLLUTION
Nutrients
LightNoiseSmell
Toxic compounds
XENOBIOTICS
Alien species
CHEMICAL ANALYSIS OF THE WATER
- Knowledge of the chemical products in the environment
- Drawbacks:
* Requires selection of substances to be tested, it is difficult and expensive
* It has little biological meaning: toxic? Synergistic, antagonistic effects?
Legal action against polluting factory
BIOMONITORING
- Chemical analysis on biota * Mussel watch, slug watch... * Bioaccumulation: fraction of pollutants that is accumulated in biological tissues
- Drawbacks: * Still need to select substances * Pollutants may not accumulate (be metabolised) * Biological meaning? (does accumulation relate to a possible impairment of animal performance?)
Slug WatchSlug Watch
BIOMARKERS: LOOKING FOR BIOLOGICAL ANSWERS
- THE MAIN AIM OF ENVIRONMENTAL TOXICOLOGY IS TO KNOW THE EFFECT OF POLLUTANTS ON POPULATIONS AND ECOSYSTEMS:
Can we measure biologically exposure to chemicals and the effects caused by them?
* Noise* Ecological relevancePopulation
Organism
Physisological
Cellular
Molecular
Community
Ecosystem
* Specificity* Speed
Biomarkersat different levels of organization
BIOACCUMULATION: low water pollutant concentrations may be concentrated in biological structures
Cd
Cl
Biota
Cells
Cellular structures
MOLECULAR AND CELLULAR BIOMARKERS
- Quick responses that precede answers at higher levels of biological organization
- Quantitative and qualitative relationships between exposure and biomarker response
* DEFINITION: alterations at the molecular or cellular level that indicate exposure to
contaminants and/or injuries induced by them (McCarthy & Shugart, 1990)
BIOMARKERS ARE APPLIED ON SENTINEL SPECIES
CELLS AND TISSUES UNDER STUDYThose showing high exposure to pollutants, accumulation rates and responsiveness to
pollutants
LiverGillsDig. glandGonads
SAMPLING STRATEGIES
Shipyard
River coming from Gernika city
** *
*
* Sampling points
STRATEGIES: ANIMAL TRANSPLANT
ANALYSIS OF PROTEINS THAT SCAVENGE SPECIFIC POLLUTANTS OR THAT CHANGE
THEIR ACTIVITY UNDER EXPOSURE
* Organophosphorous pesticides inhibit brain Acetylcholinesterase
* Organic pollutants induce enzymes of the detoxification system (CYP450)
* Metals induce Metallothionein synthesis in cells to sequester them
ST MT 1 2 3 C 1h 1d 7d det Cod Cod Turbot
14.4 kDa
MT
-lev
el(a
.u.)
6
4
2
1 h 1 d 7 d Detox.
Control0.01 ppm Cd
0.1 ppm Cd
QUANTIFICATION OF METALOTHIONEIN LEVELS
* ORGANOTINS inhibit aromatase activity
IMPOSEX, INTERSEX
Aromatase
Testosterone Estradiol
Antifoulingpaints
TBT
IMPOSEX IN THE DOGWELK
Progression of vas deferens and penis growth in a female dogwelk
POLLUTANTS ACCUMULATE IN LYSOSOMES
* Induce changes in the structure of lysosomes
LSC - FIELD STUDY Aegean Sea / Biscay Gulf
LIMANI MUSKIZ
OLYMPIADA PLENTZIA
Polluted site
Reference site
PEROXISOME PROLIFERATION
Normal rat liver Treated with PP
PEROXISOME PROLIFERATORS
Hypolipidemic drugs and other therapeutic agents
Herbicides Plasticizers
Steroids Solvents and lubricants Food flavors
Natural products
Crude oils and petroleum
products
ENVIRONMENTAL ESTROGENSChemical substances that mimic female sexual hormones
* Alter sex ratios of wild populations* Impair reproductive performance
Normal testis Intersex testis
VITELLOGENIN IN FISH a biomarker of endocrine disruption
Male fish exposed to environmental estrogens express Vtg
LiverFemale gonadE2
Vtg2
1