Related Experiment Video

Updated: Aug 9, 2025

Biochemical Measurement of Neonatal Hypoxia
13:13

Biochemical Measurement of Neonatal Hypoxia

Published on: August 24, 2011

14.1K

Fetal and neonatal bilirubin metabolism

Susumu Itoh1, Hitoshi Okada2, Kosuke Koyano3

  • 1Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan.

Frontiers in Pediatrics
|February 24, 2023
PubMed

Insights

Human fetal and neonatal bilirubin metabolism focuses on 4Z,15Z-bilirubin IXα (BR) due to immature liver function. Bilirubin IXα acts as an antioxidant but can be toxic, necessitating binding to human serum albumin (HSA) for safe transport and excretion.

Area of Science:

  • Biochemistry
  • Neonatology
  • Developmental Biology

Background:

  • Human fetal and neonatal bilirubin metabolism is characterized by limited hepatic conjugation capacity.
  • 4Z,15Z-bilirubin IXα (BR) is a lipophilic molecule with both physiological antioxidant roles and toxic potential.
  • Fetal BR excretion occurs via the placenta, while neonatal adaptation involves increased oxygen exposure.

Purpose of the Study:

  • To review the developmental and physiological roles of bilirubin metabolism in fetuses and neonates.
  • To explore the dual functions of BR as an antioxidant and a potential neurotoxin.
  • To highlight the critical role of human serum albumin (HSA) in BR transport and detoxification.

Main Methods:

  • Literature review focusing on bilirubin metabolism, transport, and toxicity in the perinatal period.
  • Analysis of the interaction between BR and HSA.
  • Examination of BR excretion mechanisms, including placental transfer and post-natal photochemical reactions.

Main Results:

  • BR is the primary form of bilirubin during fetal and neonatal development.
  • HSA is essential for solubilizing and transporting lipophilic BR in the bloodstream.
  • HSA facilitates BR excretion through photochemical reactions and prevents bilirubin encephalopathy.

Conclusions:

  • Bilirubin IXα plays a crucial, albeit complex, role in fetal and neonatal physiology.
  • Human serum albumin is indispensable for managing BR levels and preventing toxicity.
  • Understanding BR metabolism is key to managing neonatal hyperbilirubinemia and its complications.

Keywords:
4Z,15Z-bilirubin IXαbilirubin photoisomersbreast milk jaundicehuman serum albuminneonatal jaundiceoxidation productsphysiological effectsreactive oxygen species

More Related Videos

Extrahepatic Bile Duct and Gall Bladder Dissection in Nine-Day-Old Mouse Neonates06:10

Extrahepatic Bile Duct and Gall Bladder Dissection in Nine-Day-Old Mouse Neonates

Published on: August 23, 2022

2.0K
Non-invasive Optical Measurement of Cerebral Metabolism and Hemodynamics in Infants11:39

Non-invasive Optical Measurement of Cerebral Metabolism and Hemodynamics in Infants

Published on: March 14, 2013

20.5K

Related Concept Videos

Fetal Circulation01:14

Fetal Circulation

Fetal circulation is a unique system that facilitates the exchange of gases, nutrients, and waste products between the developing fetus and the mother. This intricate process takes place through a special organ called the placenta.
Two umbilical arteries transport blood from the fetus to the placenta. At the placenta, the blood absorbs oxygen and nutrients while simultaneously eliminating waste products. This oxygen-enriched and nutrient-rich blood then returns to the fetus through one...
1.1K
Inborn Errors of Metabolism01:20

Inborn Errors of Metabolism

Phenylketonuria (PKU) is a protein metabolism disorder characterized by high blood levels of the amino acid phenylalanine. This results from a mutation in the gene responsible for phenylalanine hydroxylase, an enzyme that converts phenylalanine into tyrosine. When this enzyme is deficient, phenylalanine builds up in the blood, leading to symptoms such as vomiting, rashes, seizures, growth deficiency, and severe mental retardation. An early diagnosis and a diet restricting phenylalanine intake...
217
Transcytosis of IgG01:15

Transcytosis of IgG

Transcytosis is the process in which molecules are internalized by endocytosis, transported across the cell, and released through exocytosis from the opposite end of the cell. Molecules such as insulin, immunoglobulins, and certain nutrients are transferred through the recycling endosomes by recycling and transcytosis.
IgG molecules from a mother undergo transcytosis starting around 13 weeks of gestation. The amount of IgG transferred and entering the fetal blood circulation increases with...
2.8K
Phase I Reactions: Oxidation of Aliphatic and Aromatic Carbon-Containing Systems01:19

Phase I Reactions: Oxidation of Aliphatic and Aromatic Carbon-Containing Systems

Phase I biotransformation reactions are integral to drug metabolism, predominantly involving oxidative, reductive, and hydrolytic transformations. Chief among these are oxidative reactions, which enhance the hydrophilicity of xenobiotics and introduce polar functional groups to facilitate their elimination from the body.
Oxidation reactions are fundamental in aromatic carbon-containing systems. An example is the hydroxylation of phenobarbital, a process that transforms it into...
271
Development of Immunocompetence01:22

Development of Immunocompetence

The initiation of cell-mediated immunity can be observed as early as the third month of fetal growth, with active antibody-mediated immunity following approximately one month later.
The initial cells that migrate from the fetal thymus settle within the skin and epithelial tissues lining the mouth, digestive tract, and in females, the uterus and vagina. These cells, including skin-based dendritic cells, serve as antigen-presenting cells, playing a key role in T cell activation.
Subsequent T...
403
Lifecycle of Erythrocytes01:22

Lifecycle of Erythrocytes

Erythrocytes, also known as red blood cells, constantly move through blood capillaries. As a result, they damage their plasma membrane due to the continuous friction. Typically, after 100 to 120 days, erythrocytes become rigid and fragile as they wear out. As they pass through small vessels in the spleen and liver, they can get trapped and break apart into fragments.
The resident phagocytic macrophages deal with these damaged cells by engulfing them and separating their globin and heme groups....
2.1K