Long-term objectives of this proposal are to elucidate the molecular mechanisms responsible for the therapeutic effects of phototherapy of neonatal jaundice; to improve the effectiveness and safety of phototherapy; and to define, at the molecular level, structural features that control the transport, metabolism and excretion of bilirubin and related compounds by the liver.
Specific aims are: To determine by 13C-nuclear magnetic resonance, circular dichroism and other spectroscopic methods, dissociation constants and three- dimensional structures of bilirubin, its glucuronides and its photoisomers in biologically relevant environments. To clarify the interdependent roles of vinyl substitution, intramolecular hydrogen bonding, acidity, and lipophilicity on the photobiology and biochemistry of bilirubin. To elucidate the mechanisms involved in photoisomerization reactions of bilirubin-albumin complexes and define factors that influence their stereoselectivities and quantum yields. To investigate the importance in phototherapy of a newly discovered photoisomer of bilirubin. To evaluate the contribution of the canalicular anion transporter c- MOAT to the biliary excretion of bilirubin photoisomers and other tetrapyrrolic carboxylate anions and glucuronides. To define the topography and substrate requirements of the active site of bilirubin glucuronyl transferase by studying the glucuronidation of chemically engineered bilirubins of defined three dimensional structure. To synthesize bilirubin glucuronides and novel bilirubins with potential research and clinical applications and test new chemotherapeutic strategies for inhibiting bilirubin production.
These aims will be achieved by measuring the chemical and biological properties of bilirubin and related compounds in vitro and by studying the transport and metabolism of phototherapy intermediates and bilirubin model compounds in normal rats and in mutant rats with congenital defects in bilirubin metabolism. The project is directly related to the prevention of bilirubin-induced brain damage in babies and in patients with the Crigler-Najjar syndrome, to the diagnosis and understanding the hepatobiliary disease and jaundice, and to the therapeutic and biological effects of light on humans. The work will lead to safer and more effective methods for the treatment of familial hyperbilirubinemia and jaundice in the newborn.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK026307-20
Application #
2905239
Study Section
General Medicine A Subcommittee 2 (GMA)
Program Officer
Serrano, Jose
Project Start
1980-07-01
Project End
2002-06-30
Budget Start
1999-07-01
Budget End
2000-06-30
Support Year
20
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of California San Francisco
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
073133571
City
San Francisco
State
CA
Country
United States
Zip Code
94143
McDonagh, Antony F; Vreman, Hendrik J; Wong, Ronald J et al. (2009) Photoisomers: obfuscating factors in clinical peroxidase measurements of unbound bilirubin? Pediatrics 123:67-76
Zunszain, Patricia A; Ghuman, Jamie; McDonagh, Antony F et al. (2008) Crystallographic analysis of human serum albumin complexed with 4Z,15E-bilirubin-IXalpha. J Mol Biol 381:394-406
McDonagh, Antony F (2008) Photolysis and photoisomerization of bilirubin in serum specimens exposed to room lighting. Clin Chim Acta 393:130;author reply 131
McDonagh, Antony F; Boiadjiev, Stefan E; Lightner, David A (2008) Slipping past UGT1A1 and multidrug resistance-associated protein 2 in the liver: effects of steric compression and hydrogen bonding on the hepatobiliary elimination of synthetic bilirubins. Drug Metab Dispos 36:930-6
McDonagh, Antony F; Lightner, David A (2007) Influence of conformation and intramolecular hydrogen bonding on the acyl glucuronidation and biliary excretion of acetylenic bis-dipyrrinones related to bilirubin. J Med Chem 50:480-8
McDonagh, Antony F (2007) Bilirubin toxicity to human erythrocytes: a more sanguine view. Pediatrics 120:175-8
McDonagh, Antony F; Maisels, M Jeffrey (2006) Bilirubin unbound: deja vu all over again? Pediatrics 117:523-5
McDonagh, Antony F (2006) Ex uno plures: the concealed complexity of bilirubin species in neonatal blood samples. Pediatrics 118:1185-7
Toietta, Gabriele; Mane, Viraj P; Norona, Wilma S et al. (2005) Lifelong elimination of hyperbilirubinemia in the Gunn rat with a single injection of helper-dependent adenoviral vector. Proc Natl Acad Sci U S A 102:3930-5
Woydziak, Zachary R; Boiadjiev, Stefan E; Norona, Wilma S et al. (2005) Synthesis and hepatic transport of strongly fluorescent cholephilic dipyrrinones. J Org Chem 70:8417-23

Showing the most recent 10 out of 42 publications