Bilirubin binding capacity for high-affinity site of serum albumin is:
1 gram of hemoglobin yields about 35 mg of bilirubin. Human adults form 250 to 350 mg of bilirubin per day. Bilirubin is non-polar. So, it needs a carrier in blood. Albumin plays the role of carrier. The high-affinity site can bind approximately 25 mg of bilirubin/100 mL of plasma. Loosely bound bilirubin can be easily displaced by drugs like phenobarbitone. This is why administration of phenobarbitone in premature infants can lead to kernicterus.
15 mg bilirubin/100 ml of plasma
25 mg bilirubin/100 ml of plasma
35 mg bilirubin/100 ml of plasma
45 mg bilirubin/100 ml of plasma
HAEM synth and porphyrias