HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Norlin, M. Search for Related Content PubMed PubMed Citation Articles by Norlin, M. Social Bookmarking                      What's this?

Journal of Lipid Research, Vol. 43, 721-731, May 2002
Copyright © 2002 by Lipid Research, Inc.

Expression of key enzymes in bile acid biosynthesis during development: CYP7B1-mediated activities show tissue-specific differences

Maria Norlin¹

Division of Biochemistry, Department of Pharmaceutical Biosciences, University of Uppsala, Box 578, SE-751 23 Uppsala, Sweden

¹ e-mail: maria.norlin{at}farmbio.uu.se

The developmental variation of cytochrome P450 (CYP)7A1, CYP7B1, CYP27A1, and 3ß-hydroxy-⁵-C₂₇-steroid dehydrogenase, key enzymes in bile acid biosynthesis, were investigated in pigs of different ages. As part of these studies, peptide sequences from a purified pig liver oxysterol 7-hydroxylase were analyzed. The sequences showed a high degree of identity with those of murine and human CYP7B1. Enzymatic activities and mRNA levels of CYP27A1 and 3ß-hydroxy-⁵-C₂₇-steroid dehydrogenase were similar in livers of newborn and 6-month-old pigs. Enzymatic activity mediated by CYP7A1 increased several-fold between infancy and adolescence. Hepatic CYP7A1 and CYP7B1 mRNA levels increased several-fold with age. Hepatic microsomal 7-hydroxylation of 27-hydroxycholesterol and dehydroepiandrosterone, substrates typical for CYP7B1, increased about 5-fold between infancy and adolescence whereas the activities in kidney microsomes decreased at least 10-fold. In conclusion, the results indicate that the expression of CYP27A1 and 3ß-hydroxy-⁵-C₂₇-steroid dehydrogenase are similar in livers of newborn and 6-month-old pigs whereas the levels of CYP7A1 increase. The finding that the levels of CYP7B1 increase with age in the liver but decrease in the kidney suggest a tissue-specific developmental regulation of CYP7B1. The age-dependent variation in the liver and kidney suggests that hormonal factors are involved in the regulation of CYP7B1.—Norlin, M. Expression of key enzymes in bile acid biosynthesis during development: CYP7B1-mediated activities show tissue-specific differences. J. Lipid Res. 2002. 43: 721–731.

Abbreviations: CYP, cytochrome P450

Supplementary key words cytochrome P450 • cholesterol 7-hydroxylase • oxysterol 7-hydroxylase • sterol 27-hydroxylase • 3ß-hydroxy-⁵-C₂₇-steroid dehydrogenase • hepatic 7-hydroxylation • renal 7-hydroxylation

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				A. Tevell, H. Lennernas, M. Jonsson, M. Norlin, B. Lennernas, U. Bondesson, and M. Hedeland FLUTAMIDE METABOLISM IN FOUR DIFFERENT SPECIES IN VITRO AND IDENTIFICATION OF FLUTAMIDE METABOLITES IN HUMAN PATIENT URINE BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY Drug Metab. Dispos., June 1, 2006; 34(6): 984 - 992. [Abstract] [Full Text] [PDF]

				M. Norlin, S. von Bahr, I. Bjorkhem, and K. Wikvall On the substrate specificity of human CYP27A1: implications for bile acid and cholestanol formation J. Lipid Res., August 1, 2003; 44(8): 1515 - 1522. [Abstract] [Full Text] [PDF]