Serum Markers of Environmental Stress

EPA Grant Number: R825433C070
Subproject: this is subproject number 070 , established and managed by the Center Director under grant R825433
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: EERC - Center for Ecological Health Research (Cal Davis)
Center Director: Rolston, Dennis E.
Title: Serum Markers of Environmental Stress
Investigators: Hammock, Bruce , Fry, D. Michael , Wilson, Barry W.
Institution: University of California - Davis
EPA Project Officer: Levinson, Barbara
Project Period: June 30, 1995 through June 30, 1998
Project Amount: Refer to main center abstract for funding details.
RFA: Exploratory Environmental Research Centers (1992) RFA Text |  Recipients Lists
Research Category: Targeted Research

Objective:

This project seeks to evaluate the effects of multiple stresses on the ecosystem and its components. This project will seek rapid, inexpensive, and accurate analytical methods to determine the presence of toxic chemicals in the environment. The methods can be used either for environmental monitoring or for monitoring individual organisms.

Approach:

This subproject provides rapid analytical methods for the analysis of primary toxins both in the environment and in body fluids. Assays for a variety of herbicides as indicators of environmental pollution are an example of this analytical technology. Assays for over 30 such toxins have been developed. The sensitive assay for the mercury II ion is complete. A validation study in collaboration with Burau is planned. The researchers seek to extend this assay to other toxic metals including lead and copper. These assays can be run for a fraction of the cost of competing methods yet yield data with similar or improved sensitivity, accuracy and precision. They can be formatted to be performed in mobile laboratories or in the field. Assays were developed for the insecticide carbaryl, a major group of urea herbicides, metabolites of pyrethroid insecticides which are major aquatic toxins, and the major environmental degradation product of the triazine herbicides (hydroxy-atrazine).

Indication of Exposure. Examples of these assays include the principle metabolites of the most toxic organophosphate insecticides and the most widely used herbicides, the triazines. These assays can be used to monitor urine, serum or tissue of animals to detect even very low levels of exposure. As an example of this approach we developed and validated a sensitive assay for the mercapturates of naphthalene as indicators of exposure to this material. It is a common by-product of petroleum processing and a variety of chemical processes. Investigators have developed sensitive assays for nitrophenylate-leaving groups of organophosphates to be used in parallel with the assays for acetyl and butrylcholinesterase developed by Wilson. Assays for 1-naphthol were developed because it is the major metabolite of carbaryl. This assay complements not only Wilson's serum assays, but also the assay for the parent compound. The most extensive work has been on the validation of the assay for the mercapturates of atrazine. These assays can be applied to detect even trace levels of exposure of the parent compound to indicator species.

Biomarchers of Effect. The most obvious of these is the development of highly sensitive substrates for the enzyme butrylcholine esterase (a very common marker of exposure to organophosphates). The goals are to develop more sensitive tests so that less serum will be needed from sensitive species and to develop surrogate substrates for esterases of toxicological importance as indicators of stress in wildlife species. A collaborative project will use these assays on model avian species and wild species exposed to known toxins. Many people have reported that inhibition of serum esterases is a sensitive indicator of exposure to organophosphates while results from the work of this project show that increases in serum esterases are sensitive indicators of liver damage. Affinity columns were developed for the one-step purification of esterases. These columns will be applied to purify key esterases from indicator species. In parallel work, investigators found that the soluble epoxide hydrolase is a sensitive indicator of exposure to a class of nongenotoxic chemicals known as peroxisome proliferators. It appears that this enzyme can be used as an indicator of exposure to such chemicals as phthalates in wild species. To this end, the murine and human cDNAs have been cloned and sequenced as well as the murine gene. These probes will be provided to other investigators to allow rapid cloning of the corresponding enzymes from fish species. Thus, this work covers a range of methods for monitoring the potential of exposure, actual exposure, and the effects of exposure. Because of increased interest in plant components of ecosystems we are cloning the enzyme from several plant species. Preliminary studies indicate that the induction of its message in plants is a good indicator of multiple stresses in plants including disease, drought and herbicide induced stress. Another biomarker of effect is lipid oxidation. The first application is with animals, although it should easily be extended to plants. Investigators are developing both GC/MS assays and enzyme-linked immunosorbent assays (ELISA). Techniques have been developed to co-express the above enzymes with P450s in the baculovirus system at very high levels. This system provides a eucaryotic background in a cell system with little ability to degrade foreign compounds. Rapid assays for cell death have been developed. This allows the rapid screening of diverse environmental contaminants both alone and in combination in a system where one precisely knows the enzymes involved in the activation and deactivation of these toxins. The inhibition of this enzyme is associated with permanent paralysis resulting from the exposure to some machine oils and pesticides. The analytical methods for this enzyme should be directly applicable to environmental problems.

Expected Results:

The projects listed above will be continued with several emphases. In the immunoassay area investigators expect to be responsive to needs for additional assays. Pyrethroid assays are under development at the request of Hinton, additional organophosphate assays in support of Wilson, assays for alkyl mercury and lead in support of Richardson, copper in support of Hinton and investigators expect to develope an ELISA for TCDD sensitive to low ppt in support of several projects. In addition investigators expect to advance the technology to make it more field portable, cheaper and more sensitive. Approaches include moving ELISA toward near IR based biosensors to increase signal to noise and minerurize assays, novel mathematical approaches for data analysis, and development of recombinant reporter systems and antibodies.

Supplemental Keywords:

biomarkers, bioassay, ecosystem stress, serum markers, pesticides, toxic chemicals, risk assessment, multiple stresses, ecosystem monitoring, mercury., RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Ecology, Entomology, Toxicology, Ecosystem/Assessment/Indicators, Ecosystem Protection, exploratory research environmental biology, Environmental Chemistry, Ecological Effects - Environmental Exposure & Risk, Monitoring/Modeling, Ecological Risk Assessment, Ecology and Ecosystems, Biology, Ecological Indicators, monitoring, microbiology, environmental monitoring, biomarkers, cellular biology, assays, eco-system quality, biochemical marker, enzymes, pesticides, multiple stressors, serum markers , biomonitoring, bioassay, environmental stress, toxic chemicals, ecosystem health, herbicides, serum markers

Progress and Final Reports:

1996 Progress Report


Main Center Abstract and Reports:

R825433    EERC - Center for Ecological Health Research (Cal Davis)

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R825433C001 Potential for Long-Term Degradation of Wetland Water Quality Due to Natural Discharge of Polluted Groundwater
R825433C002 Sacramento River Watershed
R825433C003 Endocrine Disruption in Fish and Birds
R825433C004 Biomarkers of Exposure and Deleterious Effect: A Laboratory and Field Investigation
R825433C005 Fish Developmental Toxicity/Recruitment
R825433C006 Resolving Multiple Stressors by Biochemical Indicator Patterns and their Linkages to Adverse Effects on Benthic Invertebrate Patterns
R825433C007 Environmental Chemistry of Bioavailability in Sediments and Water Column
R825433C008 Reproduction of Birds and mammals in a terrestrial-aquatic interface
R825433C009 Modeling Ecosystems Under Combined Stress
R825433C010 Mercury Uptake by Fish
R825433C011 Clear Lake Watershed
R825433C012 The Role of Fishes as Transporters of Mercury
R825433C013 Wetlands Restoration
R825433C014 Wildlife Bioaccumulation and Effects
R825433C015 Microbiology of Mercury Methylation in Sediments
R825433C016 Hg and Fe Biogeochemistry
R825433C017 Water Motions and Material Transport
R825433C018 Economic Impacts of Multiple Stresses
R825433C019 The History of Anthropogenic Effects
R825433C020 Wetland Restoration
R825433C021 Sierra Nevada Watershed Project
R825433C022 Regional Transport of Air Pollutants and Exposure of Sierra Nevada Forests to Ozone
R825433C023 Biomarkers of Ozone Damage to Sierra Nevada Vegetation
R825433C024 Effects of Air Pollution on Water Quality: Emission of MTBE and Other Pollutants From Motorized Watercraft
R825433C025 Regional Movement of Toxics
R825433C026 Effect of Photochemical Reactions in Fog Drops and Aerosol Particles on the Fate of Atmospheric Chemicals in the Central Valley
R825433C027 Source Load Modeling for Sediment in Mountainous Watersheds
R825433C028 Stress of Increased Sediment Loading on Lake and Stream Function
R825433C029 Watershed Response to Natural and Anthropogenic Stress: Lake Tahoe Nutrient Budget
R825433C030 Mercury Distribution and Cycling in Sierra Nevada Waterbodies
R825433C031 Pre-contact Forest Structure
R825433C032 Identification and distribution of pest complexes in relation to late seral/old growth forest structure in the Lake Tahoe watershed
R825433C033 Subalpine Marsh Plant Communities as Early Indicators of Ecosystem Stress
R825433C034 Regional Hydrogeology and Contaminant Transport in a Sierra Nevada Ecosystem
R825433C035 Border Rivers Watershed
R825433C036 Toxicity Studies
R825433C037 Watershed Assessment
R825433C038 Microbiological Processes in Sediments
R825433C039 Analytical and Biomarkers Core
R825433C040 Organic Analysis
R825433C041 Inorganic Analysis
R825433C042 Immunoassay and Serum Markers
R825433C043 Sensitive Biomarkers to Detect Biochemical Changes Indicating Multiple Stresses Including Chemically Induced Stresses
R825433C044 Molecular, Cellular and Animal Biomarkers of Exposure and Effect
R825433C045 Microbial Community Assays
R825433C046 Cumulative and Integrative Biochemical Indicators
R825433C047 Mercury and Iron Biogeochemistry
R825433C048 Transport and Fate Core
R825433C049 Role of Hydrogeologic Processes in Alpine Ecosystem Health
R825433C050 Regional Hydrologic Modeling With Emphasis on Watershed-Scale Environmental Stresses
R825433C051 Development of Pollutant Fate and Transport Models for Use in Terrestrial Ecosystem Exposure Assessment
R825433C052 Pesticide Transport in Subsurface and Surface Water Systems
R825433C053 Currents in Clear Lake
R825433C054 Data Integration and Decision Support Core
R825433C055 Spatial Patterns and Biodiversity
R825433C056 Modeling Transport in Aquatic Systems
R825433C057 Spatial and Temporal Trends in Water Quality
R825433C058 Time Series Analysis and Modeling Ecological Risk
R825433C059 WWW/Outreach
R825433C060 Economic Effects of Multiple Stresses
R825433C061 Effects of Nutrients on Algal Growth
R825433C062 Nutrient Loading
R825433C063 Subalpine Wetlands as Early Indicators of Ecosystem Stress
R825433C064 Chlorinated Hydrocarbons
R825433C065 Sierra Ozone Studies
R825433C066 Assessment of Multiple Stresses on Soil Microbial Communities
R825433C067 Terrestrial - Agriculture
R825433C069 Molecular Epidemiology Core
R825433C070 Serum Markers of Environmental Stress
R825433C071 Development of Sensitive Biomarkers Based on Chemically Induced Changes in Expressions of Oncogenes
R825433C072 Molecular Monitoring of Microbial Populations
R825433C073 Aquatic - Rivers and Estuaries
R825433C074 Border Rivers - Toxicity Studies