The bile acids play an essential role in bile water formation, the solubilization of bile constituents, and the dispersion of the products of lipolysis. The bile acids are hydroxylated, acidic steroidal substances, usually containing 24 carbon atoms per molecule. During the past decade the Principal Investigator has examined questions that relate to the development of bile acid synthesis, secretion and absorption in the newborn and fetus. In the course of the most recent of these studies, it has been shown that a new class of bile acids, with shortened side-chains, exist in the meconium of normal newborn infants. Specifically, it has been established that a C20 bile acid, 3Alpha-hydroxy-5Alpha-etianic acid, is present in meconium in quantities comparable to those of standard C24 bile acids, and that other C20-22 bile acids are also present. In the proposed studies C20-22 bile acids and certain other a typical bile acids will be studied in meconium. Their structures will be characterized definitively through the synthesis of standards, and through gas chromatogrphy-mass spectroscopy. After identification, these substances will be sought in samples of meconium from newborn infants of varied gestational age and development. Other biological materials from infants and adults, and from laboratory animals will be examined for their presence. The metabolism of these aberrant bile acids will be studied. Since certain of them are potential cholestatic agents, their effect on bile flow will be examined, and yheir occurrence in cholestatic disease of the newborn will be determined.

Project Start
1979-08-01
Project End
1986-12-31
Budget Start
1985-01-01
Budget End
1985-12-31
Support Year
7
Fiscal Year
1985
Total Cost
Indirect Cost
Name
University of Texas Health Science Center Houston
Department
Type
Schools of Medicine
DUNS #
City
Houston
State
TX
Country
United States
Zip Code
77225
Little, J M; Drake, R R; Vonk, R et al. (1995) Characterization of human liver microsomal UDP-glycosyltransferases using photoaffinity analogs. J Pharmacol Exp Ther 273:1551-9
Battaglia, E; Elass, A; Drake, R R et al. (1995) Characterization of a new class of inhibitors of the recombinant human liver UDP-glucuronosyltransferase, UGT1*6. Biochim Biophys Acta 1243:9-14
Radominska, A; Little, J M; Lester, R et al. (1994) Bile acid glucuronidation by rat liver microsomes and cDNA-expressed UDP-glucuronosyltransferases. Biochim Biophys Acta 1205:75-82
Radominska, A; Paul, P; Treat, S et al. (1994) Photoaffinity labeling for evaluation of uridinyl analogs as specific inhibitors of rat liver microsomal UDP-glucuronosyltransferases. Biochim Biophys Acta 1205:336-45
Radominska, A; Berg, C; Treat, S et al. (1994) Characterization of UDP-glucuronic acid transport in rat liver microsomal vesicles with photoaffinity analogs. Biochim Biophys Acta 1195:63-70
Radominska, A; Treat, S; Little, J (1993) Bile acid metabolism and the pathophysiology of cholestasis. Semin Liver Dis 13:219-34
Radominska, A; Little, J; Pyrek, J S et al. (1993) A novel UDP-Glc-specific glucosyltransferase catalyzing the biosynthesis of 6-O-glucosides of bile acids in human liver microsomes. J Biol Chem 268:15127-35
Panfil, I; Lehman, P A; Zimniak, P et al. (1992) Biosynthesis and chemical synthesis of carboxyl-linked glucuronide of lithocholic acid. Biochim Biophys Acta 1126:221-8
Zimniak, P; Ziller 3rd, S A; Panfil, I et al. (1992) Identification of an anion-transport ATPase that catalyzes glutathione conjugate-dependent ATP hydrolysis in canalicular plasma membranes from normal rats and rats with conjugated hyperbilirubinemia (GY mutant). Arch Biochem Biophys 292:534-8
Radominska, A; Little, J M; Lester, R et al. (1992) Hepatic metabolism of 3-oxoandrost-4-ene-17 beta-carboxylic acid in the adult rat: formation of carboxyl-linked glucuronides both in vivo and in vitro. Steroids 57:328-34

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