Hemoglobin bilirubin from degradation

TThe iron-porphyrin (heme) group of hemoglobin, released from dying erythrocytes in the spleen, is degraded to yield free Fes+ and, ultimately, bilirubin. This pathway is arresting for its capacity to inject color into human biochemistry. 

The bilirubin that is produced in phagocytic cells from degradation of hemoglobin represents the majority of the bilirubin that is produced and must be eliminated. This initially requires transport of bilirubin from the phagocytic cells to the liver. Normally, bilirubin is secreted from phagocytic cells and complexed with albumin for transport to the liver. It is essential that bilirubin is transported through the circulation bound to albumin. The toxicity of... 

A. When red blood cells lyse, hemoglobin is degraded. Bilirubin is produced from heme at an increased rate. The liver converts bilirubin to the diglucuronide at a rapid rate and excretes it into the bile. In the intestine, bacteria convert bilirubin to stercobilins, which give stool its brown color. 

In patients such as Will Sichel who have severe and recurrent episodes of increased red blood cell destruction (hemolytic anemia), greater than normal amounts of the red cell pigment heme must be processed by the liver and spleen. In these organs, heme (derived from hemoglobin) is degraded to bilirubin, which is excreted by the liver in the bile. 

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