New England Journal of Medicine Biology Diagrams Bilirubin is a metabolic product of heme, and an increase in its level may be toxic to the body. It may be conjugated or unconjugated. Encephalopathy is caused by unconjugated bilirubin has the ability to pass through the blood-brain barrier, entering the central nervous system. Conjugated forms of bilirubin result in biliary obstruction and a change in urine colour due to a decrease in excretion. Bilirubin is a yellow bile pigment produced through the breakdown of red blood cells, which is known as haemolysis. Bilirubin is processed through various organs of the GI tract before it gets excreted out of the body.In this article, we will explore the different types of bilirubin, the process of enteric bilirubin metabolism, and we will briefly explore the relevance of bilirubin to clinical
BILIRUBIN METABOLISM. Bilirubin is a breakdown product of heme (ferroprotoporphyrin IX). About 4 mg/kg body weight of bilirubin is produced each day, nearly 80% from the breakdown of hemoglobin in senescent red blood cells and prematurely destroyed erythroid cells in the bone marrow and the remainder from the turnover of hemoproteins such as myoglobin and cytochromes distributed throughout the Bilirubin is an important metabolite of heme (ferroprotoporphyrin IX), a coordination complex coordinating iron in various proteins. It is a potentially toxic substance. However, the body has developed mechanisms for its safe detoxification and disposition. Bilirubin and its metabolites also provide a distinctive yellow color to bile and stool and, to a lesser degree, urine. This topic
Gut microbiota and bilirubin metabolism: unveiling new pathways in ... Biology Diagrams
The physiological mechanisms of bilirubin action in the human body are discussed with a focus on translational importance. Bilirubin can be considered a hormone, in particular through its interaction with PPARα. Increased concentrations of blood bilirubin levels above 10 μM are associated with protection from cardiovascular and metabolic
Abstract. Bilirubin, a major end product of heme breakdown, is an important constituent of bile, responsible for its characteristic colour. Over recent decades, our understanding of bilirubin metabolism has expanded along with the processes of elimination of other endogenous and exogenous anionic substrates, mediated by the action of multiple transport systems at the sinusoidal and canalicular Metabolism of bilirubin in the human body. Bilirubin, formed from the catabolism of heme initiated by the enzyme HMOX mainly in the spleen, is transported to the liver where it is conjugated with glucuronic acid by the enzyme UGT1A. After secretion in the bile and delivery to the intestine, it is deconjugated and undergoes a series of reduction
The physiology of bilirubin: health and disease equilibrium Biology Diagrams
Bilirubin metabolism reflects the body's ability to modify and manage cellular byproducts. Once bilirubin reaches the intestines, it encounters a diverse microbiome, a community of microorganisms that play a role in its transformation. Intestinal bacteria act upon conjugated bilirubin, converting it into urobilinogen through reduction. Heme Metabolism and Disposition of Bilirubin. The largest repository of heme in the human body is in red blood cells, which have a life span of about 120 days. There is thus a turnover of about 6 g/day of hemoglobin, which presents 2 problems. First, the porphyrin ring is hydrophobic and must be solubilized to be excreted. Bilirubin is the catabolic product of heme metabolism. Within the physiologic range, bilirubin has cytoprotective and beneficial metabolic effects, but at high levels it is potentially toxic. understanding bilirubin metabolism also provides insight into the mechanisms of transport, detoxification, and elimination of many other organic anions .
