Our long-term goals are to study the mechanism(s) by which xenobiotic conjugates of lipids are formed and establish the contribution of these conjugates to the intrinsic toxicity of their parent xenobiotics. We propose to study the in vivo and in vitro formation of fatty acid and cholesterol conjugates of pentachlorophenol, chloroethanols and chloroacetic acids and also the compounds which lead to the formation of these chloroethanols and chloroacetic acid as metabolites. The xenobiotic conjugates formed will be isolated and purified using established chromatographic techniques (thin layer, gas, and high performance liquid chromatography) followed by structure elucidation using spectral techniques (ultraviolet, infrared, nuclear magnetic resonance and mass spectrometry). The toxicity of these conjugates will be characterized using morphological (histochemistry, electron microscopy) and biochemical parameters (organ function analysis using serum and target tissue enzymes) in rats. In addition, enzyme(s) involved in the formation and degradation of these conjugates will also be studied using standard protein chemistry methodologies such as enzyme assays, column chromatography, isoelectric focusing and chromatofocusing, electrophoresis, amino acid analysis, and sequencing. Although several lipid conjugates of xenobiotics have been identified within the last decade, both under in vitro and in vivo conditions, the information regarding their mechanism of formation and their contribution to the toxicity is virtually unknown. The proposed studies will lead to an understanding of how such conjugates are formed, their associated toxicity, and the enzymes involved in the formation and degradation of these conjugates.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Project (R01)
Project #
5R01ES004815-02
Application #
3252968
Study Section
Toxicology Study Section (TOX)
Project Start
1988-05-01
Project End
1991-04-30
Budget Start
1989-05-01
Budget End
1990-04-30
Support Year
2
Fiscal Year
1989
Total Cost
Indirect Cost
Name
University of Texas Medical Br Galveston
Department
Type
Schools of Medicine
DUNS #
041367053
City
Galveston
State
TX
Country
United States
Zip Code
77555
Sarkar, Swapna; Khan, M Firoze; Kaphalia, Bhupendra S et al. (2006) Methyl palmitate inhibits lipopolysaccharide-stimulated phagocytic activity of rat peritoneal macrophages. J Biochem Mol Toxicol 20:302-8
Khan, Shagufta H; Kaphalia, Bhupendra S; Ansari, G A S (2005) In vitro conjugation of ethanolamine with fatty acids by rat liver subcellular fractions. J Toxicol Environ Health A 68:667-76
Cai, P; Kaphalia, B S; Ansari, G A S (2005) Methyl palmitate: inhibitor of phagocytosis in primary rat Kupffer cells. Toxicology 210:197-204
Kaphalia, Bhupendra S; Mericle, Kelly A; Ansari, G A S (2004) Mechanism of differential inhibition of hepatic and pancreatic fatty acid ethyl ester synthase by inhibitors of serine-esterases: in vitro and cell culture studies. Toxicol Appl Pharmacol 200:7-15
Mericle, Kelly A; Kaphalia, Bhupendra S; Ansari, G A (2004) Modulation of fatty acid methyl esters in rats pretreated with tri-o-tolyl phosphate. J Toxicol Environ Health A 67:583-93
Kaphalia, Bhupendra S; Cai, Ping; Khan, M Firoze et al. (2004) Fatty acid ethyl esters: markers of alcohol abuse and alcoholism. Alcohol 34:151-8
Kaphalia, Bhupendra S; Ansari, G A S (2003) Purification and characterization of rat pancreatic fatty acid ethyl ester synthase and its structural and functional relationship to pancreatic cholesterol esterase. J Biochem Mol Toxicol 17:338-45
Mericle, Kelly A; Kaphalia, Bhupendra S; Ansari, G A S (2002) Differential inhibition of hepatic, pancreatic, and plasma fatty acid ethyl ester synthase by tri-o-tolylphosphate in rats. Toxicol Appl Pharmacol 179:119-25
Kaphalia, B S; Ansari, G A (2001) Fatty acid ethyl esters and ethanol-induced pancreatitis. Cell Mol Biol (Noisy-le-grand) 47 Online Pub:OL173-9
Khan, M F; Wu, X; Ansari, G A (2001) Anti-malondialdehyde antibodies in MRL+/+ mice treated with trichloroethene and dichloroacetyl chloride: possible role of lipid peroxidation in autoimmunity. Toxicol Appl Pharmacol 170:88-92

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