Cytochrame P-450 containing monooxygenase enzyme system metabolizes drugs, chemical carcinogens, xenobiotics and endogenous substrates in animals and man. Hamster is particularly prone to tumorigenesis, chemical carcinogenesis and metabolic disorders and consequently is an excellent animal model for study of human liver diseases. In this research proposal, we will study the induction and regulation of multiple forms of cytochrome P-450 in hamster liver and lung by drugs and carcinogens. We will isolate the major forms of cytochromes P-450 and study the enzyme level by immunotitration, reconstitution, and in vitro translation of mRNA's coding for these cytochrome P-450's. The mutiplicity of pulmonary cytochrome P-450 also will be studied in comparison with hepatic enzymes. We will also identify and purify the form(s) of cytochrome P-450 which metabolize the 7 Alpha hydroxylation of cholesterol from hamsters treated with cholestyramine. In addition, cholesterol gallstones will be produced in hamsters by feeding animals with estrogen and cholesterol. We will study the regulation of cholesterol 7 Alpha-hydroxylase activity and establish any link between this enzyme activity and cholesterol gallstone formation. Our objective of this research is to use the hamster as an animal model to understand the induction of cytochrome P-450 by drugs and carcinogens, the mechanism of activation of chemical carcinogens, and the molecular mechanism of gallstone disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM031584-03
Application #
3279725
Study Section
Physical Biochemistry Study Section (PB)
Project Start
1983-03-01
Project End
1986-11-30
Budget Start
1985-03-01
Budget End
1986-11-30
Support Year
3
Fiscal Year
1985
Total Cost
Indirect Cost
Name
Northeast Ohio Medical University
Department
Type
Schools of Medicine
DUNS #
City
Rootstown
State
OH
Country
United States
Zip Code
44272
Chiang, John Y L (2003) Bile acid regulation of hepatic physiology: III. Bile acids and nuclear receptors. Am J Physiol Gastrointest Liver Physiol 284:G349-56
Yang, Yizeng; Zhang, Ming; Eggertsen, Gosta et al. (2002) On the mechanism of bile acid inhibition of rat sterol 12alpha-hydroxylase gene (CYP8B1) transcription: roles of alpha-fetoprotein transcription factor and hepatocyte nuclear factor 4alpha. Biochim Biophys Acta 1583:63-73
Chiang, John Y L (2002) Bile acid regulation of gene expression: roles of nuclear hormone receptors. Endocr Rev 23:443-63
Chen, W; Owsley, E; Yang, Y et al. (2001) Nuclear receptor-mediated repression of human cholesterol 7alpha-hydroxylase gene transcription by bile acids. J Lipid Res 42:1402-12
Chiang, J Y; Kimmel, R; Stroup, D (2001) Regulation of cholesterol 7alpha-hydroxylase gene (CYP7A1) transcription by the liver orphan receptor (LXRalpha). Gene 262:257-65
Zhang, M; Chiang, J Y (2001) Transcriptional regulation of the human sterol 12alpha-hydroxylase gene (CYP8B1): roles of heaptocyte nuclear factor 4alpha in mediating bile acid repression. J Biol Chem 276:41690-9
Marrapodi, M; Chiang, J Y (2000) Peroxisome proliferator-activated receptor alpha (PPARalpha) and agonist inhibit cholesterol 7alpha-hydroxylase gene (CYP7A1) transcription. J Lipid Res 41:514-20
Chiang, J Y; Kimmel, R; Weinberger, C et al. (2000) Farnesoid X receptor responds to bile acids and represses cholesterol 7alpha-hydroxylase gene (CYP7A1) transcription. J Biol Chem 275:10918-24
Stroup, D; Chiang, J Y (2000) HNF4 and COUP-TFII interact to modulate transcription of the cholesterol 7alpha-hydroxylase gene (CYP7A1). J Lipid Res 41:11-Jan
Wu, Z; Martin, K O; Javitt, N B et al. (1999) Structure and functions of human oxysterol 7alpha-hydroxylase cDNAs and gene CYP7B1. J Lipid Res 40:2195-203

Showing the most recent 10 out of 44 publications