Loren Data's SAM Daily™

FBO DAILY ISSUE OF AUGUST 11, 2004 FBO #0989
SOLICITATION NOTICE

A -- Enantiomer Selectivity in Toxicity of Vinclozolin to Medaka Fish

Notice Date

8/9/2004
 

Notice Type

Solicitation Notice
 

NAICS

541380 — Testing Laboratories
 

Contracting Office

Environmental Protection Agency, Office of Research and Development, Ecosystems Research Division (LAB), 960 College Station Rd., Athens, GA, 30605
 

ZIP Code

30605
 

Solicitation Number

PMB4322
 

Response Due

8/19/2004
 

Archive Date

9/3/2004
 

Point of Contact

Beverly Owensby, Procurement Point of Contact, Phone 706-355-8010, Fax 706-355-8026, - Beverly Owensby, Procurement Point of Contact, Phone 706-355-8010, Fax 706-355-8026,
 

E-Mail Address

Owensby.Anne@epa.gov, Owensby.Anne@epa.gov
 

Description

STATEMENT OF WORK Enantiomer Selectivity in Toxicity of Vinclozolin to Japanese Medaka Fish Background Endocrine disrupting chemicals have the potential to adversely impact reproductive processes. Many environmental pesticides are known to possess endocrine disrupting properties. The dicarboxyimide fungicide vinclozolin has been shown to induce cytochrome P450 in both mice and rat mammalian systems. These monooxygenase enzymes are responsible for the hydrolysis of the parent vinclozolin and the known end-products have been shown to possess antiandrogenic properties in both mammals and fish. Vinclozolin is a chiral compound; that is, it consists of two species called enantiomers ? mirror image isomers that usually differ in their fate and effects. For example, it is well known that in the great majority of cases enantiomers differ in their rates of microbial transformation, leading to selective occurrence of one over the other in the environment and biota. Now it is deemed important to test the enantiomers of various pesticides for differences in their toxic properties, since both toxicity and occurrence must be considered in making risk assessments. In the present case, a species of a fish ? the Japanese medaka ? will be employed in a new approach to assay the two separate enantiomers of vinclozolin for differences related to the induction of cytochrome P450 enzymes. This induction, as mentioned above, has already been proven for racemic vinclozolin (a mixture of equal amounts of the two enantiomers), but no work has been done with separate enantiomers to show any differences in their activity. In addition, preliminary results indicate that more than one cytochrome P450 enzyme is being induced by vinclozolin upon exposure to the medaka. This can be verified by separation and detection of the enzymes from the medaka liver using electrophoresis measurements followed by mass spectrometric protein characterization ? the modern science of proteomics. The hypothesis upon which this contract is based is that the induction process will operate at different rates for the two vinclozolin enantiomers, and that more than one cytochrome P450 enzyme is induced. Requirements The Contractor shall perform the following tasks: 1. Quality Assurance: Prepare a Category 4 Quality Assurance Project Plan (QAPP). The Plan shall be delivered by the Contractor to the EPA Technical Coordinator and the Contracting Officer within 21 days after award of the contract. The QAPP will be approved by the EPA within 7 days after receipt, after which time work can commence on the effort. A copy of the approved QAPP must be forwarded to the Contracting Officer. 2. Exposure: Exposure systems shall consist of three separate chemicals ? the two separated enantiomers of vinclozolin and the vinclozolin racemate, each at a concentration of 1.25ppm in the aquarium water ? as well as a control without vinclozolin. Each chemical and the control shall be exposed in duplicate to 10 medaka fish for 72 hours to induce measurable amounts of cytochrome P450 monooxygenase. Thus, the exposure regimen will require 8 exposure chambers and 80 fish. 3. Liver Sample Preparation: Microsomal isolates shall be prepared from the livers of the medaka that have been exposed as directed in 2 above. Each of the 8 exposures shall require excision of liver tissues from the 10 fish, their combination and homogenization, and isolation of endoplasmic reticulum fragments in the form of a microsomal fraction corresponding to each exposure. 4. Proteomics: The 8 microsomal isolates shall each be separated into their protein components by gel electrophoresis, visualized by appropriate reagents, and their quantity measured by fluorescence spectroscopy. Comparison of protein bands and their quantities between enantiomers, the racemate and the control will indicate which proteins have been regulated by exposure to the various forms of vinclozolin. Important bands shall be picked by robotic equipment and automatically submitted to the mass spectrometer for possible identification of the protein. 5. Final Report: A final report giving experimental procedures and results in both hard copy and electronic form (WordPerfect or Word) shall be submitted to the Technical Coordinator and Contracting Officer within 6 months after award of contract. 6. EPA Provisions: The EPA will provide the racemic vinclozolin and separate vinclozolin enantiomers to be used in this work. Procurement Point of Contact: Anne Owensby U.S. EPA, NERL, ERD 960 College Station Rd. Athens, GA 30605 PH: 706 355 8010, FAX: 706 355 8026 Owensby.Anne@epa.gov
 

Place of Performance

Address: US Environmental Protection Agency, 960 College Station Rd.,, Athens, GA

Zip Code: 30605

Country: US
 

Record

SN00639985-W 20040811/040809212733 (fbodaily.com)
 

Source

FedBizOpps.gov Link to This Notice
(may not be valid after Archive Date)

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